ML20203F611
| ML20203F611 | |
| Person / Time | |
|---|---|
| Site: | Millstone  |
| Issue date: | 02/11/1999 |
| From: | Andersen J NRC (Affiliation Not Assigned) |
| To: | Bowling M NORTHEAST NUCLEAR ENERGY CO. |
| References | |
| NUDOCS 9902180206 | |
| Download: ML20203F611 (7) | |
Text
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February 11, 1999
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D' l
l Mr. Martin L. Bowling, Jr.
i Recovery Officer - Technical Services Northeast Nuclear Energy Company 1
c/o Ms. Patricia A. Loftus E
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Director-Regulatory Affairs f
P. O. Box 128 4
Waterford, Connecticut 06385 g j l
SUBJECT:
REQUEST FOR A TECHNICAL REVIEW OF A DRAFT INFORMATION 5
NOTICE DESCRIBING THE INADVERTENT DISCHARGE OF CARBON DIOXIDE AND GAS MIGRATION AT MILLSTONE UNIT 3
Dear Mr. Bowling:
The U.S. Nuclear Regulatory Commission is planning to issue an information notice (lN) which describes the inadvertent discharge of a carbon dioxide fire suppression system in the cable spreading room at Millstone Unit 3 on January 15,1999. This IN is being issued to alert other facilities as to the potential personnel safety hazards and operational complications associated with such a discharge.
We request that you review the enclosed draft IN to ensure the technical information regarding jj p
the event is accurate. If we do not receive written comments from you by February 24,1999, u
L we will assume that you do not h::vs any comments. Your cooperation in this matter is appreciated.
l l
Sincerely,.
[
hOf James W. Andersen, Project Manager Project Directorate 1-2 Division of Reactor Projects - 1/11 Office, of Nuclear Reactor Regulation m
Docket No. 50-423
Enclosure:
As stated cc: See next page DISTRIBUTION:
TClark JAndersen WDean Docket File OGC JDurr, RI PDI-2 RF PUBLIC ACRS DScrenci, RI CPetrone i
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Lillian M. Cuoco, Esquire Mr. F. C. Rothen Senior Nuclear Counsel Vice President - Nuclear Work Services Northeast Utilities Service Company Northeast Utilities Service Company P. O. Box 270 P. O. Box 128 Hartford, CT 06141-0270 Waterford, CT 06385 l
Edward L. Wilds, Jr., Ph.D.
Ernest C. Hadley, Esquire Director, Division of Radiation 1040 B Main Street j
Department of Environmental Protection P.O. Box 549 79 Elm Street West Wareham, MA 02576 Hartford, CT 06106-5127 Mr. John Buckingham Regional Administrator, Regioni Department of Public Utility Control l
U.S. Nuclear Regulatory Commission Electric Unit 475 Allendale Road 10 Liberty Square King of Prussia, PA 19406 New Britain, CT 06051 First Selectmen Mr. James S. Robinson, Manager Town of Waterford Nuclear Investments and Administration 15 Rope Ferry Road New England Power Company Waterford, CT 06385 25 Research Drive Westborough,MA 01582 Mr. Wayne D. Lann'ng, Director i
l Millstone inspections Mr. Raymond P. Neo:i Office of the Regional Adre.'nistrator Vice President - Nuc ser Oversight and 475 Allendale Road Regulatory Affairs King of Prussia, PA 19406-1415 Northeast Utilities Service Company P. O. Box 128 Mr. M. H. Brothers Waterford, CT 06385 Vice President - Millstone Operations Northeast Nuclear Energy Company Deborah Katz, President P.O. Box 128 Citizens Awareness Network Waterford, CT 06385 P.O. Box 83 Shelbume Falls, MA 03170 Mr. M. R. Scully, Executive Director Connecticut Municipal Electric Mr. Allan Johanson, Assistant Director l
Energy Cooperative Office of Policy and Management l
30 Stott Avenue Policy Development and Planning Normch,CT 06360 Division 450 Capitol Avenue - MS# 52ERN l
Mr. John Carlin P. O. Box 341441 Vice President - Human trvices Hartford, CT 06134-1441 Northeast Utilities Servic,, Company P.O. Box 128 Waterford, CT 06:25 I
I' Millstone Nucle:r Power Station Unit 3 p
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cc:
Ms. Terry Concannon Mr. William D. Meinert l
Co-Chair Nuclear Engineer Nuclear Energy Advisory Council Massachusetts Municipal Wholesale Room 4100 Electric Company Legislative Office Building P.O. Box 426 l
Capitol Avenue Ludlow,MA 01056 i
Hartford, CT 06106 1
Mr. Evan W. Woollacott Co-Chair Nuclear Energy Advisory Council 128 Terry's Plain Road Simsbury, CT 06070 l
I Mr. John W. Beck, President Little Harbor Consultants, Inc.
Millstone -ITPOP Project Office P.O. Box 0630 Niantic, CT 06357-0630 Mr. Leon J. Olivier Chief Nuclear Officer-Millstone Northeast Nuclear Energy Company P.O. Box 128 Waterford,CT 06385 Mr. Chris Schwarz l
Station Director Northeast Nuclear Energy Company 1
P.O. Box 128 Waterford, CT 06385 Senior Resident inspector Millstone Nuclear Power Station clo U.S. Nuclear Regulatory Commission P. O. Box 513 Niantic, CT 00357 Nicholas J. Scobbo, Jr., Esquire Ferriter, Scobbo, Caruso, & Rodophele, P.C.
l 75 State Street,7th Floor i
Boston,MA 0210 i
Citizens Regulatory Commission i
ATTN: Ms. Susan Perry Luxton 180 Great Neck Road j
Waterford, CT 06385 4
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I UNITED STATES NUCLEAR REGUt.ATORY COMMISSION OFFICE OF NUCLEAR REACTOR REGULATION WASHINGTON, D.C. 20555-0001 March XX,1999 NRC INFORMATION NOTICE 99-XX: INADVERTENT DISCHARGE N DIOXIDE FIRE PROTECTION SYSTE AND GAS MIGRATION Addressees x
All holders of licenses for nuclear power, research, a inst reap and f ~
isosilties A'
e; Purpose n' %
The U.S. Nuclear Regulatory Commission (NRC) is is g tis information notice to alert addressees to potential personnel safety hazards and operational complications asscciated with discharge of carbon dioxide (CO2) fire protection. systems. It is expeded that rcei;;ients will review the information for applicabluty to theirfacilities and consider adens, as appropr;ste.
However, suggestions contained in this infonnation are not NRC requirements; therefore, no specific action or written response to notice
./
Background
E
$3 At Duane Amold Unit 1 on Marcht2,1992 (LIR 331/92-004), the licensee performed a special test of the CO2 fire suppression system inee cable apreading room. This test was conducted to check corrective actions taken following a CO2 discharge in 1990. At the time of this test, the reactor had been sp and defueled. As a result of this test, CO2 had intruded into the control (xwn; this intrusettled to an unacceptable reduction in area oxygen level within s few i
- minutes, levels of (at chest level) and 15 percent (at floor level) were
- recorded, levels were the plant acceptance criterion of 19.5 percent. Essential i
control room psisonneldonned ained breathing apparatus (SCBA) and were able to remain in the 6ontrol room. ' The lowered oxygen levels were caused by increased pressure in the cable spreading'rmom which is directly beneath the control room. Sealed penetrations between the two room ~
arnder the high differential pressure.
,.9 ly 28,1998, at a
National Engineering and Environmental Laboratory, during ration for system preventive maintenance, a high-pressure CO2 fire suppression unexpected
'ctuated. The room in which workers were located was filled instantly i
. hiteout conditons. Workers did not have the means of escaping safely.
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ining was not provided; exit pathways were not clear; and, emergency apparatus, exit pathway lighting, and emergency ventilation were not available. The resulted in one fatality, several life-threatening iriuries, and significant risk to the safety of the initial rescuers. The Accident investigation Board determined that since 1975 there have been a total of 63 deaths and 89 injuries resulbng from accidents involving the discharge of CO2 fire suppression systems.
r Enclosure
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IN 99-XX g
March xx,1999 Page 2 of 4 Description of Circumstances On January 15,1999, at 5:53 p.m., with the plant at full power, an inadvertent discharge of the CO2 fire suppression system occurred in the Millstone Unit 3 cable spreading room. At Millstone 3, the cable spreading room is located in the control building directly below the control room The actuation was caused when a non-licensed plant equipmentoperator trainee in the service building blew dust off a printed circuit board (which was'hUbsequently determined to be defective) located in the cable spreading Joom CQt control panel. The panel is located in the service building, not the control building..
wsIra po. plant personnelin the cable spreading room at the time of the discharge. S
' after the,dsestge, CO2 was fouhd to have migrated down into the switchgear rooms directlybelow thep~apreadirig' room. Approximately 37 min'utes after initiation, the lidensee used's portable y~ ~ ~ to I
I measure the concentration of CO2 in one of the Cor,tipl,8ulling stairwells (whmetallows access to the control room, the cable spreading room and the switchgear rooms). The reading was off-scale high indicating that the CO2 concentratio@ in siccess of 50,000 parts per million (ppm). The current NRC Regulatory Guide 1.7(reconunended toxicity limit for CO2 is 10,000 ppm'. On the basis of this indication, the licensee declared the" area uninhabitable.
Mk YU erators aligned the[ control building purg Apprcximately 2 hours2.314815e-5 days <br />5.555556e-4 hours <br />3.306878e-6 weeks <br />7.61e-7 months <br /> after the CO2 dischargelop'JThe awltchgear room system to remove CO2 from the switchgeafrooms.
purging first because they contained important plant 5^quipment,iidch as the auxiliary shutdown panel. The purge system is Enon-safdty-related System designed to remove CO2 and smoke from various control building areas.% Placing the purge system in service diverted air from the control room to the swifilohgear rooms whici)hwered the pressure in the control
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allowed CO2 from the cable spreading roo/This lowering of pressure in the cont room relative to the cable spreadmg room m to migrate up through penetrations into the control room. When the concentration of CO2 reased 5000 ppm in the control room, the operators donned _sielf-contained tirmathin0' apparatus (SCBA) as required by their procedures. The i
concentration'of CO2 in thementrol room reached a peak level in excess of 17,000 ppm before j
it began to decrease.sThe o5erators wore SCBA for approximately 6 hours6.944444e-5 days <br />0.00167 hours <br />9.920635e-6 weeks <br />2.283e-6 months <br /> until the CO2 was successfully p from the co room 2xyg%
' y' Discu Sk
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$0h A redew of this event b f the licensee identified several design and personnel safety issues, cable spreading rodun CO2 system is designed to automabcally actuate in response to a
.?The system is e%of CO2 to allow time to evacuate the cable spreading ped with alarms to wam personnel in the cable spreading room of an
' ding discha k
,./
rrent NRC toxxuty limit for CO2, -*I in Reg. Omde 1.78, is 10000 ppm. Plant m
- exposed to CO2 need to be protected by self e=*=inad breathmg apparatus before this aanraerstmo is reached In the proposed revisma to Reg. Guide 1.78, the toxxaty limit for CO2 was raised to 40000 ppm. This new limit is based on the Immediately Dangerous to Life and Health (IDLH) l anac=*ranon of CO2, establinhad by the Natenal lastatute for C-w=:=1 Safety and Health (NIOSH).
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IN 99-XX
.A March xx,1999 I
Page 3 of 4 previous occasions, plant operators intervened to prevent falso actuation signals from causing CO2 discharges in the cable spreading room. The licensee had previously modified automatic CO2 fire protection systems in other areas of the plant so that they could only be actuated manually. After this event, the licensee disabled the automatic function of the CO2 system for the cable spreading room and implemented appropnate compensatory measures The licensee y
is evaluating permanent changes to avoid future inadvertent CO2 d rges The migration of CO2 into three separate fire zones may ad aNected the operators' ability to shut down the plant during a fire in the cable 7Asevere fire in the cable spreading room may adversely affect the operat ability to safely shutdown the plant from the control room. in the event that the operators required tersvahqststhe control room, plant procedures require operators to shutdown plant)6m the audll5ryshutdown panel and other panels which are located in the swit spams. During this"twent,the CO2 concentration at the auxiliary shutdown panel would socess without SCBAP in 1994, the licensee suspended the formal SCBA trajaMg quellfication program for plant operators except those who were members of the firetrige 1995 the licensee established a site wide fire brigade which did not include planjeperators so SCBAtraining and 3
6 qualification requirements were suspended foJ em also. This ation was based on projected post-accident radiation levels and4htrusion of toxic gases Jrito the control room.
However, this determination failed to consider CO24 gas as4 commended in NRC Regulatory Guide 1.78. Fortunately, dynng this gdent, was available in the control room area and at various other locations around the pee. Althojgh training and qualifications for all plant operators were not current, pl the plant,dperators that were on shift during the event had previously been trained and qualflod with ty SCBA ardconsequently they were able to perform their duties using the SCBA. To prove corrimunication between the operators, the licensee replaced the Un SOBA with from Unit 2 which had an improved type of radio communjattion system addition, som,got the operators did not have corrective lenses which Were compatible the SCBA face masks. As an immediate corrective action the licensee re qualified all plant qperators for SCBA use. The licensee is evaluating the need to reinstate the1BCBA qualificationprogram for plant operators on a permanent basis. This suspension of,$CBA qualification was for plant operators only and did not affect fire brigade members and qu'alified.
w:..
The rge of CO2 'kfieAecurity alarm on the cable spreading room door. A security off
'was instructed t the door alarm but to not open the door. The guard entered the 11 and ascended, stairs to the cable spreading room. Upon approaching the cable ding room, the r smelled wintergreen (which is discharged with the CO2 to produce odor for person safety) and was engulfed in a mist that he concluded was CO2. The held his 6th and rapidly exited the building. The licensee's root cause team
--- ;;$)that procedures for isolating areas potentially affected by CO2 be reviewed.
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r IN 99-XX March xx,1999 I
Page 4 of 4 This information notice requires no specific action or written response, if you have any questions about the information in this notice, please contact one of the technical contacts listed below, the appropriate regional office, or the appropriate office of Nuclear Reactor Regulation (NRR) Project Manager.
i
, 8x%e A
n David B. Ma
, Dir qh j
Division of tor Prog gernent j
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Office of lear Reha t, ' Reg 'kkyf Technical contacts:
Beth Korona, Region 1 Fr Region 1
'M 860-447-3170 61 4
E-mail: bekanrc.aov E-m-pfk Chuck Petrone, NRR 4
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G, 301-415-1027
/
E-mail: cdo@nrc.aov ef Attachments:
f
- 1. List of Recently issued NMSS Info
. ion N s
1
- 2. List of Recently issued NRC Inf ion No' s
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