IR 05000267/1988021

Insp Rept 50-267/88-21 on 880926-30.Violation & Deviations Noted.Major Areas Inspected:Implementation of & Compliance to Safe Shutdown Requirements of 10CFR50,App R

ML20206L976
Person / Time
Site:	Fort Saint Vrain
Issue date:	11/21/1988
From:	Ireland R, Murphy M, Seidle W NRC OFFICE OF INSPECTION & ENFORCEMENT (IE REGION IV)
To:
Shared Package
ML20206L974	List: IR 05000267/1988021 ML20206L970 ML20206N085 ML20206N091
References
50-267-88-21, NUDOCS 8811300329
Download: ML20206L976 (24)

Text

.____ _ ______ _ _ _

. . . .

.

.

APPENDIX C

'

U.S. NUCLEAR REGULATORY COMMISSION

REGION IV

NRC Inspection Report: 50-267 Operating License: DRP-34 Docket: 50-267 Licensee: Public Service Company of Colorado (PSC)

2420 W. 26th Avenue, Suite 15e Denver, Colorcdo 80211 Facility Name: Fort St. Vrain (FSV)

l Inspecsion At: FSV Site Weld County, Colorado

!

Inspection Conducted: September 26-30, 1988

<? -

Inspectors: ,. "/>///r M. E. Murphy hReactor Inspector Test Programs Date Section, Division of Reactor Safety

'

1 / /

/

- f~1 //fL/f/ /

R. E. Ireland,/ Technical Assistant Division Date of Reat. tor ~ Safety

Accompanying Personnel: D. J. Kubicki, Fire Protection En0ineer Office of Nuclear Reactor Regulation C. B. Ramsey, Reactor Inspector, Region V .

'

K. Sulli'/an Technical Specialist, BNL

,,

/

/

Approved * *

, 'N/[U W. C. Seidley Chief. Test Programs Section Date Division of Reactor Safety ,

i i

y Q K 05ooo$0 p7  ;

PN

_ _ _ _ _ - _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ . _ _ _ _ _ _ _ _ _ _ _ _ _ _ ___

. ~ .

.

.

Inspection Summary Inspection Conducted September 26-30, 1988 (Report 50-267/88-21)

Areas Inspected: Nonroutine, ernounced inspection for implementation of and compliance to the safe shutdown requirements of 10 CFR 50, Appendix Within the areas inspected, or,e violation was identified (failure to follow procedure, paragraph 5). Two deviations were identified (failure to upgrade fire penetration seals and failure to provided for use of temporary ventilation fans, paragraph 5).

. Results: The fGcus of the inspection was on the adequacy of licensee performance in the area of fire protection and prevention. It included an assessment of the ability of plant systems to etiable safe' shutdown to be achieved and maintainea following a fire. This effort included a review of the licensee's safe shutdown methodology as described in the licensee's "Appendix R Evaluation" as well as an evalustion of plant emergency shutdown procedures and active and passive fire protection features such as fire barriers and automatic fire protection system Despite the one level V violation and two deviations delineated in the report, the inspection team cuncluded that the licensee had comprehensively addressed NRC fire protection requirements and guidelines. The licensee's technical approach toward providing fire protection for safety systems can be considered

,

conservative. Plant modifications were implemented in a qualified manner and, i generally in accordance with the approved implementation schedule. During the walkdown of the emergency shutdown procedures, plant operating personnel and fire brigade representatives displayed a high isvel of training and

,

expertise. With the exceptien of one location, the plant appeared to be free

of transient combustibles and other fire hazards.

.

. _ _ _ _ _ _ _ _ . _ _ _ . _ _ _ _ _ _ _ _ _ _ - - _ _ _ _ _ _ _ _ _ _ _ _ _ - _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _

...

>

.

DETAILS 1. Persons Contacted PSC H. Brey, Manager, Nuclear Licensing and Resources P. Tomlinson, Manager, Quality Assurance (QA)

M. Deniston, Superintendent of Operations R. Williams, Jr., Vice President, Nuclear Operations D. Warembourg, Manager, Nuclear Engineering G. Schmalz, Fire Protection Program Manager, FPE M. Niehoff, Nuclear Design Manager M. Holmes, Nuclear Licensing Manager L. Vickery, Nuclear Licensing Technical Writer D. Bonadies, Nuclear Engineer (Electrical)

R. Gunnerson, Nuclear Design Supervisor E. Hicks, Nuclear Engineer, Senior Designer F. Tilson, Engineering Assurance Manager F. Trujillo. Engineering Assurance Engineer M. Ferris, Manager. QA Operations M. Cappello, Manager, Central Planning and Scheduling G. Bates, Supervisor, Nuclear Projects C. Stolley, Technical Training Supervisor L. Sutter, Supervisor, QA Auditing D. Seymour QA Engineer, Auditor M. Block, System Engineer Manager L. Scott, QA Services Manager F. Borst, Nuclear Training Manager J. Gramling, Supervisor, Nuclear Licensing, Operations H. O'Hagan, Outage Manager, NPD TENERA H. George, Vice President J. Setka, Manager, Electrical, I&C NRC R. Farrell, Senior Resident Inspector All personnel listed above attended the exit intervie . Followup of Previous inspection Findings (92701)

(Closed) Unresolved item (267/8323-01): Reactor Buildicq Fire Components Separation, Fire Detection, and Suppression Do Not Meet Appendix R

!

i _

____ ___ _ _ _ _ _ _ _ _ ._

. , ,

.

Requirements - An exemption anu SER were issued May 10, 1988, that i resolved this issue. This item is close '

(Closed) Unresolved Item (267/8323-02): Turbine Building-Auxiliary !

Boiler Room Fire Areas Do Not Meet Appendix R Requirements for Component !

Separation, Fire Detection, and Suppression - An exemption and SER were !

issued May 10, 198S, that resolved this issu This item is close ,

(Closed)UnresolvedItems(267/8323-03;267/8323-04;267/8323-05): The Three-Room Complex Fire Areas Do Not Meet Appendix R Requirements for Component Separation, Fire Detection, and Sup3ression - An exemption and SER were issued May 10, 1988, that resolved t115 issue. These items are close t (Closed) Unresolved Item (267/8323-06): The Alternative or Dedicated

,

Shutdown Capability Criteria of Appendix R,Section III L Could Not Be Met -

l An exemption and SER were issue May 10, 1988, that resolved this issu i This item is closed, l

(Closed) Unresolved Item (?67/8323-07): The Associated Circuits Analyses ,

] Were incomplete - This inspection reviewed these areas in detail. This

'

'

. Item is considered resolved based on this inspection, the details of which l l are in paragraph 3. This item is close j (Closed) Unresolved item (267/8323-08): BTP 9.5-1 Appendix A Concern E

• The licensee does not have within its organization or as a consultant l l a qualified fire protecticn eng1ncer who is responsible for

fannulation and implementation of the fire protection progra !

The licensee now has a full-time fire protection engineer who is the !

i fire protection program manage '

<

• An approved fire retardant coating has not been applied to all

non-IEEE 383 qualified cable (Only those cables in the three-room

,

control complex and within 10 feet of the "G" and "J" walls have been

! coated).

l l

The licensee has not subjected the type of electrical cable used at l

FSV to the current IEEE No. 383 flame test requirements. Instead, a

, flame retardant coating of Flamemastic 71A or asbestos cloth has been

applied to specific areas of the electric cable tray system. The l

extent and ruthod of application is described in Attachments 1 and 3 i to PSC Letter P-75024, dated December 15, 1975; PSC Letter P-76104, dated May 10, 1976; and resolution to Question No. 12 in PSC Letter P-76135, dated June 18, 1976. These fire protection measures, which retard the spread of fire between electric cables serving

,

I l redundant safety-related equipment and prevents the loss of redundant l

circuits due to an exposure fire, have been reviewed and accepted by the NRC for plant operation.

l l

l

!

_ _ _ _ _ _ _ _ _ _ _ _ _ _ _ __- __ _

. . .

1,

-

.

l i

.

Fixed emergency lighting, consisting of sealed beam units with

! individual 8-hour minimum battery supplies have not been installed in I

the areas required for safe shutdown and in access routes to these

,

,

areas.

!

! Exemption request was granted May 10, 198 Paragraph 4 of this i inspectior, report contains additional details, d

i j

Fire detection systems in the plant do not conform to the requirements of NFPA Standards Nos. 72A and 7EE for area-wide coverag Additional fire detection capability has been added throughout the plant and an exemption request was granted May 10, 1988, i  !

j The power supply to the mo_t_cro driven fire pur) is routed in the room  ;

'

i containing the diesel fire pum Therefore, both pumps could be

,

disabled in a single fire in the diesel pump room.

The motor driven pump has been provided within an independent  :

'

alternate cooling method (ACM) power suppl * I i The outside P.I.V-type control valves for the fire water distribution system are not supervised in accordance with NFPA 5tandard No. 1 P J The applicable standard is NFTA No. 26 which allows the valve to be -

sealed and the conduct of a weekly documented surveillance. The

licensee is complying with this requiremen *

The water spray nozzles for the cable tray fire suppressions system

! are obstructed bylray covers, which is not consistent with the stipulatio.is of Section 4-4.1.4 of NFPA 5tandard No. 1 t

. The original design of the congested cable tray area spray system

! called for the cable tray covers to remain in place. This installation was previously approved by the NRC.

i

'

) * The control valves for the manually-activated water spray systems along the "G" and "J" valls are not located outside of the area of l

fire influence and would, therefore, be inaccessible during a fire, I which is not consistent with Section 4.7.1 of NFPA 5tandard No.1 [

These systems have been converted to automatic system l

-

This item is close }

t

!

, 3. List of Documents Reviewed l i

See Attachrent to this repor [

}

l'

.

i b

,

t

. _ _ .

_ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ - _ _ _ _ _ _ _ _ _ _ _ _ _ __

. . .

.

4. Emergency Lighting System The plant is presently equipped with hard-wired, essential / emergency backup lighting systems powered from the standby diesel generators and the plant DC system. However, these systems are not sufficiently independent so that they are assured to be available in the event of a fir In Appendix R. Evaluation Report No. 4, the licensee comitted to install a new system for the reactor and turbine buildings. Outlying structures requiring access for post-fire shutdown functions that are not covered by ACM-powered lights will be covered by 8-hour battery lights. The new emergency lighting system will have the following attributes: Wiring and lights configured so that multiple physically separate systems would result with each system covering a zone or quadran Lighting equipment in each zone will be separated by a minimum of 30 feet from that of another zone. Loss of any one zone because of a postulated fire would be compensated for by the lights in the adjacent zones, including permanently installed movable "extension lights" where necessary; Separate and independent power feeds for each zone covered; Electrical power supplied from the ACM diesel; Breaker coordination so that only one circuit would fail given the loss of any one individual light unit, or a single fault such as due to a fire; A minimal number of lights per circuit so that the lighting availability loss would be minimized given a circuit loss; A mix of local area lights and spot flood beams plus extension lights where necessary; Receive a field check /walkdown to confirm adequate numbers, locations, and positioning of light Essential valve operators or equipment components requiring manual operator action (s) will be covered by local zone lighting and/or spot beam Therefore, if a fire failed the local circuit, the spot beams from a distance greater that 30 feet would still be functional. In addition, extension lights will be available in selected areas where valves are located in upper gallerie By letter dated May 10, 1988, the Office of Nuclear Reactor Regulation issued its safety evaluation relating to the proposed safe shutdown system and exemption requests concerning 10 CFR part 50, Appendix R for FS Section 2.8 of this safety evaluation report (SER) discusses the licensee's request for exemption from the technical requirements of Section !!I.J of

_ _ _ _ - _ _ _ _ _ _ - _ _ - _ - _ _ _ _ _ _ _ _ - . _____-_ __

<. .

i

!

Appendix This section was found during this inspection to document a FSV comitment to provide circuit breaker coordination for the ACM l

.

emergency lighting power system. Such coordination would ensure that only i one lighting circuit would fail in the event of loss of any one individual

'

lighting circui At the time of this inspection, it was determined that the ACM emergency lighting coordination evaluation was incomplete. The licensee is currently performing this evaluation as part of the emergency lighting .

modifications which are scheduled for completion in the late spring of

1989. The circuit breaker coordination of ACM powered emergency lighting i

will remain an open item pending the final completion of the emergency i

lighting modificatinns (267/8821-n1).

i .

l S. Review of Plant Modifications (64100) [

! In conjunction with their efforts to comply with the fire protection i requirements delineated in Appendix R to 10 CFR 50 and supplementary ,

plant-specific guidance issued by the staff, the licensee comitted to  ;

>

implement cert?in plant modifications. These modifications were [

sumarized in the five volume Appendix R compliance assessment report and  !

subsequent correspondence. NRR has reviewed this information and has j

,

prepared a SER (dated May 10,1988), which approves the licensee's y 1 approach to satisfying Appendix R. This approval was conditioned on the 4

'

implementation, by the licensee, of their comitment to the above  !

referenced modifications. The following plant modifications were ,

inspected: l

'

Installation of fire barrier penetration seals, f f *

Provision of portable ventilator fans for the three-room complex, i

Selected cable rerouts for shutdown related system !

]

In addition, plant conditions, such as combustible loading in areas for i which the licensee had requested exemptions from the requirements of  !

Appendix R to 10 CFR 50, were inspected to validate the licensee's

justification for the exemptions, j

,

i

) No nonconfontance was observed during the inspection of the following [

]

cable rerouts for shutdown related systems:  ;

I j

'

Bearing water makeup pumps 1 *

Surge tank level instrumentation

! *

Feedwater flow monitoring .

] Feedwater flow associated cables  !

a

ACM fuel oil transfer pump [

' * Helium flow instrument cables l '

Main steam temperature indication f

!

Bearing water pumps  !

l Emergency water booster pump  !

l l

l l

. - _ _ . ._ . _ _ _ _ _ _ _ _ . - _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ . _____ - _ - - _ _ _ _ _ _ _ - _ _ . _

. c .

!

8 i

Turbine water removal pumps

• Fire water pump transfer switch In the Appendix R Evaluation (Report No. 4, "Exemptions and ,

Modifications"), the licensee comitted to upgrade the fire barrier c penetration seals in the following areas to a full 3-hour fire rated  !

design: l

West wall of the three-room complex

Diesel generator rooms  !

• Auxiliary boiler room

Turbine lube oil reservoir room

Turbine lube oil storage room During this inspection, the NRC inspectors observed two penetration seals in the auxiliary boiler room that were not 3-hour rated. The condition .

represents an apparent deviation frorr the licensee's comitmen l (267/8821-02) ,

Also, 4 the Appendix R Evaluation (Report No. 4 "Exemptions and l Modifications"), the licensee identified certain locations where a fire could cause loss of normal ventilation to the three-room complex. The .

licensee comitted to provide portable fans which would achieve a  ;

comparable level of ventilation in these rooms such that room temperatures I would not rise above the acceptable temperature limits of the electrical  !

equipment in these room j During this inspection, the NRC inspectors determined that the licensee f had not performed an analysis to justify the use of portable fans to 1

'

compensate for loss of normal ventilation. In addition, the use of the portable fans is not reflected in the post-fire safe shutdown procedure l

. Also, an independent source of power for these f ans has not been provide !

I These conditions represent an apparent deviation from the licensee's

! comitment. (267/8821-03)  ;

i

! While conducting the area walkdowns for determining general conditions  !

such as combustible loading, the NRC inspectors identified an apparent radwaste storage area on Elevation 4771 feet of the reactor building.

Combustibles observed in this location included plastic containers, a l cardboard drum, and other Class A-type combustible material. The

,

licensee's Procedure P-8, "Fire Fighting and Prevention," governs, among i

other things, the admission, safe use, and storage of combustible l l

materials and flamable liquide in the plant. The procedure states, j J

"Combustible usage within plant operating areas shall be kept to an }

absolute minimum . . . ;" and "Flamable items, such as some Anti-C  !

!

clothing and wiping rags, must be kept in a noncombustible bin or container until required;" the procedure also states, "The use of  !

( combustibles in plant operatirg areas may be allowed temporarily and only [

'

l

'

l

,

!

l i

'

- - - - - - , -- . - , . , . . _ _ , - - . . , . - - - . , . - . _ , - - - _ - , _ _ - - - - _ , . . - , , - _ _ - . - - - .

-

_ _ - _ _ _ _ _ _ _ _ _ - _ _ _ _ _ _ - _ _ _ _ _ __ _ _ _ _ _ _ _ _ _ _ _ _ _ . __ __ _

.

c .

.

I when immediate use is intended; combustibles must be removed from the area

,

when not being used."

The licensee confirmed that a radwaste storage area had been established in the reactor building at Elevation 4771 feet. This storage area and the combustibles within it had not been identified in the Appendix R

'

evaluation report or in the justification provided in conjunction with the licensee's exemption request for the reactor building. This condition, therefore, represents an apparent violation of Combustible Control Procedure P-8. (267/8821-04) Post-Fire Safe Shutdown Capability Reactor Building The inspection team verified that the entire reactor building is a single fire area encompassing an upper refueling floor mezzanine, lower refueling floor mezzanine, refueling floor, prestressed concrete reactor vessel (PCRV), auxiliary equipment areas, and a keyway (basement and subfloor pit below the PCRV). The PCRV extends vertically through all levels of the building interior (approximately 200 fee". The floor / ceiling assembly at each elevation of the buildir.; consists mainly of open mesh steel grating. There are no fire rated floor / ceiling assemt' lies to prevent flame propagation, heat transfer, or products of combustion from spreading throughout the vertical height or circumference of the interior of the buildin The licensee requested and was granted an exemption from Section Ill.G.2 of Appendix R by the NRC for the reactor building because it contains redundant systems, components, and associated electrical circuits required for safe post-fire safe shutdown /cooldow The equipment and associated electrical circuits involved include the turbine water removal pumps, bearing water pumps, bearing water makeup pumps, primary coolant, and steam generator instrumentation. The principal fire hazards in the reactor building were verified to be hydraulic oil associated with the hydraulic power units and the helium circulator turntable, lubricating oil, and combustible electrical cable insulation. Fire protection features provided for the reactor building include automatic sprinkler protection for the hydraulic oil and concentrations of combustible electrical cable insulation fire hazards, area wide fire detection, fire hose stations, and portable fire extinguisher The NRC's approval of the licensee's exemption request for the reactor building was based on the fire detection and suppression features in addition to spatial separation of redundant shutdown trains and the installation of a third turbine water removal pum The inspection team verified that the third turbine water removal pump was installed and would be operable prior to startup from the

_ - . . . . - . . . - - _ _ - . . -. _ - . - .

. ; .

l

'

,

l l current obtage. In addition, the team verified the adequac redundant shutdown train separation in the following areas:y of (1) Reactor Building Level 1 (Elevation 4740 Feet, 6 Inches) ,

Safe shutdown /cooldown equipment located on this level is as follows:

Helium purification cooling water pumps

Helium dryer units

Bearing water cooling pumps

Steam water dump tank

Hydraulic power units

Turbine water drain tank s Turbine water removal pumps  !

Buffer helium circulators i Buffer helium coolers

Bearing water removal pumps '

'

Bearing water accumulators and pressurizers  !

Helium recovery compressors  :

Redundant equipment was verified to have the spatial separation required by the exemption. In addition, the team verified that the oil supply for the helium circulator turntable hydraulic unit located beneath the PCRV is removed during normal reactor operation, and the hydraulic oil supply for the two hydraulic ,

power unita located in the southwest corner of the area are '

separated by a 2-hour fire-rated wall and protected by automatic sprinklers. Furthermore, it was verified that concrete curbed i enclosures are installed to contain the discharge of oil from these individual accumulators and water from automatic !

sprinklers up to 500 gtllon !

t (2) Reactor Building Level 2 (Elevations 4756 and 4759 Feet)

This level contains the lower part of the PCRV. Inside the PCRV [

support ring, are located steam generator and helium j penetrations, high pressure separators, main steam, reheat !

steam, and feedwater piping. Outside the support ring are I hydraulic oil operated valves and auxiliary system piping. An I auxiliary equipment area is located in the east quadrant. Safe g shutdown /cooldown equipment located on this level is as follows: i

Steam generator penetrations [

'

Helium circulator penetrations [

High pressure separators j

Main steam piping -

• Reheat steam piping f

Feedwater piping  :

Hydraulic oil operated valves l

!

t

.

- - - - - - - - . - - - - - - - - - - - - - - - - . - _ - _ _ - - - - - - - - _ - - - - _ _

- - - - - _ _ __ _ _ --_ ____ ,

. ,

,

.

,

Auxiliary syste piping

Bearing water makeup pumps

Purification heat exchangers Redundant shutdown /cooldown equipment was verified to have the spatial separation required by the exemptio (3) Reactor Building Level 6 (Elevations 4811 and 4816 Feet)

This level contains PCRV and auxiliary equipment consisting of PCPJ relief valve piping, main steam valve piping, ventilation equipment, electrical cables, gas waste surge tanks, liquid waste receivers, and monitor tank Safe shutdown /cooldown equipment located on this level is as follows:

PCRV relief valve

6-inch main steam vent valves Redundant shutdown /cooldown equipment was verified to have the spatial separation required by the exemptio No violations or deviations were identified in the review of this program area, b. Turbine Building Level 5 (Elevation 4791 Feet)

This area is enclosed to the north by a concrete block wall except for the 480V switchgear room concrete wall and the masonry block turbine lube oil storage room wall. A concrete block wall to the west separates the service building and the turbine building. Walls on the south and east sides are turbine building walls that are constructed of dual corrugated steel enclosing mineral wool as thermal insulation. The floor is concrete with several concrete lined pits. The ceiling of the area is constructed of partially reinforced concrete with many open areas and steel gratin Hydraulic oil operated valves are located above the open areas and steel grating is on Level 6 of the turbine buildin Safe shutdown /cooldown equipment located on this level is as follows:

Emergency water booster pumps

Condensate pumps

ACM service water return transfer switch Redundant safe shutdown /cooldet.n equipment was verified to have the spatial separation required b' ,the exemptio No violations or deviatior.. were identified in the review of this program are '. . .

.

c. Uses and Capacity of Fire Protection Water Supply The fire protection water supply at this facility is a. multiple purpose system. It provides water supply for fire extinguishment as well as primary and secondary reactor cooling functions. The system is supplied by two fire pumps (one electric and one diesel driven)

with a rated capacity of 1500 gallons per minute at 125 psi eac The pumps take suction from independent sumps which are connected to the main cooling tower basin; water is supplied from two 13,000,000-gallon ponds via a circulating water makeup pt.M ,

For a postulated fire in a safety-related area, the greatest expected water flow for fire extinguishment is the combined flow required for automatic sprinklers and manual fire fighting hose station Deficiency No. 6 of the licensee's internal QA Audit Report No. 88-0M3 identifies the concern that the greatest expected flow rate for required fire extinguishment, when the helium circulator turntable automatic sprinkler system and manual hose stations are actuated, may not be met by the existing capability of the fire pumps. The licensee is pursuin Corrective Action Request (CAR)g resolution to this concern through No. 88-0 For the cases where the fire water system is used to provide primary or secondary reactor shutdown cooling functions, the fire pumps have adequate capacity. In these modes of operation, the greatest expected flow demand from the fire pumps is when they are used to provide forced circulation cooldown. The flow requirements for this case are 200 gpm for hydro-motive force to a helium circulator and 1050 gpm for steam generator makeu This combined flow of 1250 gpm is not required until approximately 90 minutes after a fire has occurred with consequential interruption of forced circulation cooling. At that time, the licensee indicated that the inner fire ring header would be isolated to preclude spurious actuation of automatic fire suppression syttems. The inspection team expressed the concern that the isolation of manual and automatic water supplied fire suppression capability approximately 90 minutes after a fire occurrence to achieve reactor shutdown cooling functions could lead to a competing process if the fire is not extinguished within this time fram The licensee acknowledged the teams' concern and indicated that their position for this case would be further evaluate This is considered an open item (267/8821 05) pending further licensee action, d. Shutdown Procedure Walkdown and Postulated Fire Scenarios For a congested cable area fire, the licensee implemented Abnormal Operating Procedure (A0P) No. 4801 for the ACM. For noncongested cable area fire occurrences resulting in an interruption of forced circulation, the licensee has implerrented Safe Shutdown /Cooldown (SSC)

Procedure No. 0 __ _ _ _ _ _ _ _ _ _ _ - _ _ _ _ _ _ _ - _ _ _ _ _ _ _ _ _ _ - _ - _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ - _ _ - _ _ _

,

.. .

.

,

i l Based on the facility's unique design features, the inspection team recognized the distinct difference between this gas cooled reactor and the light water reactors to which the criteria of Appendix R to 10 CFR 50 are nonnally applied by the NRC. This facility has two primary means of achieving and maintaining safe reactor shutQwn/cooldow In either case, the control rods and/or the i reserve shutdown system is used to shutdown the reactor and maintain

a subcritical reactivity conditio The decay heat removal can be performed by forced circulation cooling or by PCRV liner cooiing.

. These cooldown methods have been analyzed by the licensee and found to be acceptable by the NRC. In addition, the team determined that there exist multiple and redundant means for achieving and 1 maintaining either of the two cooldown modes that have been reviewed by the NRC but not explicitly analyzed as alternatives for achieving

, safe shutdown cooling, j To challenge the licensee's post-fire safe shutdown capability, the

inspection team postulated two fire scenarios. One scenario could be i characterized as being beyond of the scope of the fire hazard

analysis and the design basis fire protection features provided j (spatial separation of redundant trains in addition to automatic fire

detection and suppression in a fire area). The intent of the i scenario was to create the limiting event of an interruption of l forced circulation as analyzed in Section 14.4.2.2 of the FSV FSA The other scenario can be characterized as within the scope of the

'

fire hazard analysis and the design basis fire protection features l

provided, with the intent of challenging the licensee's ability to

determine the availability of redundant trains that are protected by j spatial separation, j The licensee provided one shift supervisor and one equipment operator l

to demonstrate implementation of Procedure No. SSC-03 for both of the 4 fire scenarios. Both fire scenarios were postulated in noncongested I cable areas in the reactor building and turbine buildin i

!

(1) Turbine Building Fire Scenario In the first fire scenario, the inspection team postulated the receipt of a fire alarm in the control room from level 5 of the turbine building. In response, the shift supervisor dispatched an operator to verify the alarm. Upon arrival in the area, the operator reported back to the shift supervisor that the area was filled with dense smoke, and flames were coming from the vicinity of the "B" emergency water booster pump. The shift supervisor notified the fire brigade. Upon arrival of the fire brigade leader, a "size up" of the situation was simulated and the brigade leader confi med that the "B" emergency water booster pump was involved in fire. In addition, he determined that a cable tray at the ceiling level and oil on the Level 5

- - _ - - _ - - _ - - _ - _ - - _ _ _ _ _ _

'

.

.

turbine building floor were on fire. The oil fire on the floor was spreading south in the direction of the "A" condensate pump (the horizontal distance between the "B" emergency water booster pump to the north and redundant "A" condensate pump to the south is approximately 50 feet). Furthermore, the automatic sprinkler system for the open cable trays at ceiling level along the north wall had failed and the fire had propagated east along the cable trays and was headed south on the cable trays. The source of the oil leak was from hydraulic oil operated valves located on Level 6 of the turbine building. The oil leak had not been isolate To combat the fire, the fire brigade leader informed the shift supervisor that the fire brigade was required to be in full turnout gear. Two brigade members would attack the fire from the east turbine building floor entrance, and two brigade members would attack from the south entrance with one and 1/2-inch fire hose fog streams. The shift supervisor acknowledged the fire brigade leader's strategy for attacking the fire and gave the brigade leader the "OK" to proceed. In attacking the fire from the south entrance, the brigade members had to extinguish the cable tray fire at the ceiling level and the oil fire on the floor, which had reached the condensate pump pi In the process of this extinguishment effort, the "A" condensate pump was lost due to water damage from the fire hose stream. The redundant "B" emergency water booster pump had been lost as a result of fire damage that was caused by the pump's ignition of the leaking oil from the hydraulic oil operated valves located on Level 6 of the turbine building. The loss of both pumps caused the loss of forced circulation cooling of the reactor cor Although the shift supervisor was not expecting such a scenario, the instructions and contingency action, available to him in the system based Procedure No. SS-03 led to his making a determination of whether offsite power was available. Once the determination was made that offsite power was available, the decision was made to use the firewater system to restore forced circulation. Had offsite power not been available, the diesel fire pump rather than the electric pump could have been used, in addition, there are multiple alternate means tha*. have not been analyzed, but could have been used to restore circulation (e.g., use of other emergency water booster or condensate pumps by crosstieing power supplies). In a scenario such as this one where the redundant shutdown pumps have failed and it is postulated that all of the alternate means of achieving and maintaining forced circulation had also failed, as a last resort, the licensee can implement the ACH using Procedure No. ADP 4801. The shift supervisor stated that if attempts is restore forced circulation cooling were unlikely to succeed, he

. - _ _ _ _ _ _ _ - _ _ _ _ _ _ _ - . . _ _ _ _ . _ _ _ _ .

'

. .

,

.

.

4 would have resorted to this procedure within the time

constraints required, in order to ensure reactor l depressurization and core cooling via the PCRV liner cooling .

syste (2) Reactor Building Fire Scenario I In the second fire scenario, the inspection team postulated the

receipt in the control room of multiple fire alarms from

,

throughout the reactor building. In response, the shift supervisor dispatched an operator to v1rify the alarms. The operator entered the reactar building at Level 5 and reported back to the shift supervisor tM the entire reactor building was filled with dense smok The fire brigade was sumone Upon the fire brigade leader's arrivil at Le wi 5 of the reactor building entrance, he detemined that brigade full turnout gear was recuired and t<rigade members would pair off in twos. He decidec that cae pair of brigade members would enter the reactor building at the same level and search down to level 1 to discover the location of the fire. During the search for the origin and 109 tion of the fire, the brigade leader info ued the shift supervisor the reactor building ventilation had been lost and temperatures inside the reactor building were extremely ho Beca9se of visibility obstruction by the dense smoke, there was no way to determine what systems had been or would be damaged by the fir The shift supervisor established alternate reactor building ventilation in response to this scenario but had to rely totally on diagnostic instrumentation to determine the availability of redundant rains of shutdown equipment. The fire was eventually located and determined to involve oil storage on Level 1 of the reactor building and electrical cables in the vicinit However, during the period the fire brigade was searching for the location of the fire there was uncertainty about redundant train availability and the affects of the fire on diagnostic instrumentation accurac The licensee agreed with the inspection team that both of these scenarios illustrated the need to enhance the decision making process of shif t supervisors to determine the availability of shutdown equipment that is free of fire damage. To enhance this process. the licensee indicated that Procedure No. SSC-03 would be revised to direct shift supervisors to instruct the fire brigade to protect one redundant train when a fire in the vicinity involved the other trai '. ,.  ;

i

.' r e

e. Pre-Fire Plans The inspection team reviewed the licensee's prefire plans to determine the adequacy of fire fighting strategies planned for fire occurrences in each safety-related fire area. With one exception, the prefire plans appeared to contain adequate strategy and information for attacking fires, identifying hazardous materials, and the location of safe shutdcwn equipmen The one exception concerns water filled mechanical components such as piping and valves necessary for safe shutdown /cooldown. The 6-inch redundant main steam atmospheric relief valves (manually operated)

are located in the north quadrant of Level 6 of the reactor building and are required for safe shutdown /cooldown. The prefire plan for this area indicates that there are no safe shutdown components located in this area. The licensee's explanation for the omission of these components from the prefire plans was that due to the length of the list of water filled mechanical components it was not practical to list them all in the prefire plan However, the licensee indicated that the prefire plans were currently being revised and an appropriate reference to the location of these components would be included in the current revision of the prefire plans. The need for this reference to valve location was illustrated during the turbine building fire scenario described above, when it was observed that the equipment operator did not ininediately know the location of the atmospheric relief velves when directed to them by the shif t superviso f. Safe Shutdown Procedures (1) Procedure Review The NRC inspectors reviewed a number of procedures relating to fires and subsequent restoration of forced circulation core cooling in the event of a fire in a noncongested cable area, and for cooling via the liner cooling system in the event of a fire in a congested cable are Procedure SSC-03 is the basic systems procedure which makes provision for restoration of forced circulation core cooling via use of Appendix R Train A or Train B depending on availabilit This procedure is clearly written, and defines those operator and monitoring actions necessary to cope with a loss of forced circulation cooling event resulting from a fire. For the most part, equipment locations are clearly identified; however, as noted above, this procedure does not identify the location of the 6-inch atmospheric steam relief valves, nor are they identified in the prefire plan. The licensee stated that this would be corrected. The licensee also committed to provide in

- -_-- __ --------- -_ ----.--_-- _ -- - - ---- _- - ---------_ -- _ --

- - - - _ - - - - _ _ _ ,

.. ,

,,

.

.

this procedure clarification of train availability determination

'

as made by the shift supervisor based on fire locatio Procedure AOP 48-01 pertains to assurance that the reactor

vessel is depressurized and the liner cooling system is

, functioning in the event of permanent loss of forced circulation l cooling capability. It is applied to fires involving congested

'

cable areas, including the control room, the cable spreading room and the 480 V switchgear room. This cooling method was approved previously and the procedure has been previously subjected to NRC review and walkdown Procedure SSC-01 makes provision for backfeed of power from the ACM diesel generator to reenergize essential 480 V buses via the

!, 4160 V buse It is clearly written and is considered l acceptabl This procedure is used only as a contingency i measure in the event of 108s of offsite power and failure of the normal emergency diesel generator .

The foregoing procedures are system based. However, two other procedures. EP-1 and EP-G, provide symptom based matrices for

'

fires and for loss of active cooling situations with or without fir These matrices provide quick reference to ininediate actions and to the appropriate systems based procedures; they a provide an effective outline for management of the consequences i of fire i During the two fire scenarios described above, the inspectors observed effective and integrated utilization of these

procedures. The licensee's crew also referred to procedure

! EP-Class, Attachment C10 for classification and reporting of the emergency action levels of these scenarios.

,

No violations or deviations were identified in the review of this program are ,

(?) Procedure Training The NRC inspectors reviewed the lesson plan fer training of crews in the use of SSC-01 through SSC-0 This training material is considered adequate. A typical syllabus used for one of these procedures was also reviewed and found to be adequat It was confirmed that all shift crews had received i

this training and that appropriate plant walkthroughs of the procedures had been conducted. Interviews of selected plant i personnel showed a knowledge level that could only be gained through appropriate trainin _ _ _ _ . _ _ _ _ _ _ - _ _ _ _

,- - .

. '

,

.

,

.

'

.

(

!

l The NRC inspectors emphasized two aspects of training to l licensee personnel. First it was apparent that periodic inplant

'

procedure walkthrough training would be needed to assure that shift crews retain adequate knowledge of the locations of i various components that might have to be manipulated to restore and preserve cooling capability. Second, it was apparent that training should cover those alternatives for restoring and preserving core cooling capability through use of various combinations of plant equipment prior to resorting to the procedures discussed above. While these procedures must be  !

invoked if time constraints dictate, it would be desirable to i try one or more of the various methods normally available to ;

restore core cooling before resorting to these last-resort i procedure l No violations or deviations were identified in the review of *

i this program are l 7 protection for Associated Circuits j

! i

Coninon Buss Concern  ;

i f The comon buss associated circuit concern arises when safety-related !

i or nonsafety-related circuits share a comon power supply with  !

post-fire safe shutdown circuits and:  ;

i

' ' The associated nonessential circuits are not provided with an l acceptable level of separation from the required circuits as !

stated in Sectier, III.G. of Appendix R to 10 CFR 50, and; j

• The required power source is not provided with coordinated

! electrical fault protection to ensure that fire induced faults L on associated cables will be isolated by an electrical l protective device located nearest to the fault, prior to i propagating to a trip of any protective device located upstream r of the required supply, ,

in addition, an alternative method of achieving compliance, such as I manual operator action to shut nonessential circuits from required f power sources, has been found to provide an acceptable method of j achieving compliance provided such actions are governed by written procedures and may tse accomplished in a timely manne The licensee's rethod of compliance with this concern was found to -

) incorporate a ccebination of the protection options described abov !

For the 480V AC system, the licensee's analysis was found to take i i credit for manual operator actions to shed all nonessential loads l l from required power sources. The required actions were found to be t sdequately addressed within the post-fire safe shutdown operating j l

pr ocedures. In addition, due to the amount of time available to i i

!

'

_ . - - .

- - _ _ _ _ _ _ _ _ _ _ - _ _ _ _ _ _ _ _ _ _ - _ _ _ _ _ _ _ - _ _ _ _ _ _ _ _ _ - _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ -

'

.

.

.

implement such procedures at this type of facility the required actions may be accomplished within an acceptable time fram For the 125V DC control power and 120V AC instrumentation circuits, the licensee's analysis was found to take credit for coordinated electrical protection of power sources relied on to achieve post-fire safe shutdow These power sources are located within the congested cable area (CCA) and are only used in the everit of fire outside of this area. Therefore, associated circuits of concern are defined as those cables which are routed outside the CCA and share a comon power source with required equipmen (1) Circuit Coordination Circuit coordination is audited by reviewing a representative sample of time-current characteristic curves developed for electrical protective devices associated with required shutdown power source The intent of this review is to verify that fire induced faults will be isolated by the individual load protective devices prior to the fault propagating to a trip of the upstream power supply feeder breake A random sampling of circuits powered from required 125V DC control power sources and 120V AC instrumentation power sources revealed satisfactory short circuit coordination capabilit This review included 125V DC Distribution Panel 1A and 120V AC Distribution Panel 1A. No deficiencies were identified during this review and the licensee's protection for these supplies was found to be acceptabl (2) High impedance Faults The high impedance fault concern is found in the cases where multiple fire-induced faults may exist as loads on a power supply required to achieve safe shutdown. Such faults are postulated to be of a value which is just below the trip point of the individual load circuit protective device The occurrences of a sufficient number of such faults within a given fire area may result in a trip of a required power supply feeder breaker and, therefore, would cause the loss of the required power source. Clearing such faults on associated circuits, which may affect safe shutdown, may be accomplished by manual breaker trips governed by written procedures. A detailed evaluation of tte potential effects of high impedance faults is not required if it is assumed that the shutdown capability will be disabled by such high impedance faults and appropriate written procedtres for clearing them are provided (reference Generic Letter 86-10, Section 5.3.8).

._ _

. ..

. I e

[

The licensee's analysis has detennined that required 480V power r supplies are susceptible to loss due to fire initiated high :

impedance faults. The licensee has implemented written procedures which direct operators to shed nonessential loads and reload onto the bus only those circuits which are required to :

achieve post-fire safe shutdow !

The 125V DC control power supplies were found to be potentially vulnerable to loss due to the occurrence of such faults. For these supplies, however, it was determined that the licensee's procedures did not provide the necessary guidance for operators to perform nonessential load shedding. In response, PSC nas conunitted to perform a detailed evaluation of the required '

125V DC control power supplies and, if required, implement any necessary modifications or revisions to existing procedure Pending the licensee's final resolution of the potential loss of t required 125Y DC control power supplies, this wil' sain an 1 unresolved ite (267/8821-06)  ;

.

b. Spurious Signals Concern [

The spurious signals concern arises when the potential exists for f fire initiated grounds, shorts or open circuits to cause false motor, control, and instrument indications such as those that occurred i during the 1975 Brown Ferry nuclear plant fire. This concern also !

includes the consideration of spurious operation of other components :

that would adversely affect safe shutdown capabilit l The licensee has performed a comprehensive analysis of this concer [

This evaluation was found to identify those valves in the designated ;

flow paths whose spurious opening could result in a significant :

diversion of flow. As a result of this evaluation, mitigating i actions have been incorporated into the FSV post-fire safe shutdown i procedures. A review of Attachment 1 to SSC-03, recovering from a l nonconges*ed cable area fire resulting in an interruption of forced i circulation, found it to provide the operator with necessary I contingency actions, such as manual valve operations, which may be ;

necessary to mitigate fire initiated spurious valve operations. A i review of the licensee's analysis and trethodology for mitigating l potential spurious operations did not identify any deficiencies and ;

given the pount of time available to implement these actions at this !

facility, the spurious signal associated circuit concern was found to !

be adequately addresse [

c. Comon Enclosure f The corron enclosure associated circuit concern is found when i redundant circuits are routed together in a raceway or enclosure and !

they are not electrically protected or fire can damage both circuits !

due to inadequate fire barrier penetration l l'

I

!

. . . _ - - - _ - - - - -_ -- - - - - - - - - - _ - - - _ _ - - . - - - - - - - - _ - - - - - - - - - - - - - - - - - . - - - - - - - _ - - - - - - - - - - - - - - - - - -

.. .,

.'

.

It should be noted that the fire protection portion of this concern 1 (i.e., adequacy of fire barrier penetrations) is addressed in paragraph 5 of this report. The electrical portion of this concern was found to be satisfactorily addressed when a sample of associated nonessential cables which share a comon enclosure with required "

circuits was found to be provided with adequate electrical fault ,

current protection. Based on the sample of circuits selected for review, the licensee's electrical arotection for assot, lated circuit !

which share a conron enclosure witi required circuits, was found to ,

be acceptabl ;

\ Cable Routing J

During the inspection, the routing of cables associated with the following redundant safe shutdown components was reviewed to verify the adequacy of separation in accordance with the requirements of Appendix R,Section III.G.2. This evaluation was performed by i reviewing color coded cable raceway drawings provided by the  ;

license l Train A Component Train B Component PDI-1157-2 PDI-1158-2 i C-7301 C-73025 >

P-2106 P-2107  :

'

P-3106 P-2110

• ihis review identified numerous ema991es of modifications and rerouting of cables performed by the licensee to achieve an i acceptable level of compliance with the separation requirements of l Section ll!. Nt ;eficiencies were identified during this revie t 8. Communications Portable radios have been designated as the primary means of comunication l during the implementation of post-fire safe shutdown procedures. The ,

licensee has performed tests of its existing radio system to verify the adequacy of the comunications capability. These tests have identified  !

.

several "dead spots" within the plant where radio comunication is ~

! inadequate. As an interim corrective action, the licensee has implemented ,

i an operations order which identifies the location of the radio "dead i spots" and instructs the operators to move to an area where radio

!

communications are known to be acceptable, j he licensee's long term entrective action plan includes the installation I l of a new radio comunication system. This new system will incorporate a repeater system which is expected to eliminate the comunication dead

'

'

spots which currently exist. This system has been Jescribed to NRC i Region IV in a letter dated March 9, 198 *

r

-

l l

1 L

. . -_---

._ --.._ _- __-..-- _ _ _ - - _ _ _ , _ , . _-- . . - .. - . - - - - _ - - _ - -

- _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ -_____ _ ____ - ____ __ _ __ __-___ ___ _ _ _ - _ _ _ - _ _ _ - _ _ _ _ __ - - _ _ _ _ _

- .

.

,. .

• ,

i 22 1 i

Comunications will remain an open item pending the final implementation and testing of the new comunication system (267/8821-07).  !

.

! 9. Exit Interview i i  ;

An exit interview was conducted on September 30, 1988, with the personnel i denoted in paragraph 1 of this report. At this interview, the scope of the inspection and the findings were sumarized. The licensee did not

identify, as proprietary, any of the information prcvided to, or reviewed by, the NRC inspector ,

L i i

.

I i

,

.

'

-

!  !

!

>

!

l '

!

!

i {

! i

>

!

!

J 2 [

i

l

t

) l i i I l

\ t i  !

1  !

l 1 l

i

!  :

I J l

!

-

1 .

4  !

(____.,_____,._.,..___,_ _ . . _ _ . _ . _ _ _ _ _ _ _ _ . . _ , . _ . . . , . , _ - - _ _ _ . _ , . _ . _ _ , - . . _ ,

'

.

,

s'

.

ATTACHMENT DOCUMENTS REVIEWED Date Number Re Title Procedures 09/19/86 EE-92-0007 - Evaluation of Low Voltage Distribution Networks 06/14/88 SSC-01 2 Restoration of Power to Essential 480 Volt Busses 06/14/88 SSC-03 2 Recovering From a Noncongested Cable area Fire Resulting in an interruption of Forced Circulation 06/15/87 Lil 070.00 - Lesson Plan: Safe Shutdown Coolin Procedures (SSC-01 through SSC-05)g 09/23/88 A0P-48-01 2 Alternate Cooling Method System 12/15/87 - - Fort St. Vrain Fire Protection Program Plan 05/09/88 EI I 54 Discussion of Fire / Fire System Action Matrix 06/30/88 IP G 54 Loss of Active Core Cooling / System Action Matrix 04/87 Vols. 1-5 Appendix R. Evaluation: Fort St. Vrain Nuclear Generating Station Reports 1-5 Drawings 08/25/81 E-49 NL Elec. Epulp. Turb. Bldg. North Flan Below Elev. 4829'-0" 07/22/87 E-46 JP Elec. Equip. Turb. Bldg. South Plan Below Elev 4811'-0" l 08/12/87 E-47 AM Elec. Equip. Turb. Bldg. South Plan Below Elev. 4829'-0" l

07/14/87 E-48 UW Elec. Equip. Turb. Bldg. North Plan Below Elev. 4811'-0" 07/27/87 E-50 07 Elec. Equip. Turb. Bldg. North Mis Plans and Sections L

._ - _ _ _ _ _ _

.

.

.'

09/02/86 E-52 PH Elec. Equip Turb. Bldg. South Mis Plans and Sections 08/08/86 E-57 KF Elec. Equip. Reactor Bldg. Plan Below Elev. 488'-8" 12/29/87 E-58 AT Elec. Equip. Reactor Bldg. Plan Below Elev 4869'-0" 08/15/85 E-59 AM Elec. Equip Reactor Bldg. Plan Below Elev. 4849'-0" and 4839'-0" 07/22/87 E-60 AT Elec. Equip. Reactor Bldg. Plan Below Elev 4829'-0" 10/10/86 E-61 CB Elec. Equip. Reactor Bldg. Plan Below Elev. 4816'-0" and 4811'-0" 01/27/87 E-62 FH Elec. Equip Reactor Bldg. Plan Below Elev. 4801'-0" and 4791'-0" 09/30/87 E-63 JR Elec. Equip. Reactor Bldg. Plan Below 4769'-0" 09/30/87 E-64 JR Elec, Equip. Reactor Bldg. Plan Below Elev 4759'-0" and 4756'-0"

,

l

,

. , . . - . .

-

, -