ML20136J316

Forwards Questions Re Manual Operations & Instrumentation Based on Review of 841116-1217 & 850117 & 0401 Submittals of App R Safe Shutdown Models.Addl Info Requested within 30 Days of Ltr Receipt

ML20136J316
Person / Time
Site:	Fort Saint Vrain
Issue date:	11/01/1985
From:	Butcher E Office of Nuclear Reactor Regulation
To:	Lee O PUBLIC SERVICE CO. OF COLORADO
References
TAC-54373, NUDOCS 8511250332
Download: ML20136J316 (5)

Text

t November 1, 1985 Docket No. 50-267 Mr. O. R. Lee, Vice President Electric Production Public Service Company of Colorado P. O. Box 840 Denver, Colorado 80201

SUBJECT:

FORT ST. VRAIN - APPENDIX R SAFE SHUT 00WN MODELS -

REQUEST FOR ADDITIONAL INFORMATION

Dear Mr. Lee:

We are reviewing your submittals dated November 16, and December 17, 1984, January 17 and April 1,1985 concerning your fire protection evaluation of Fort St. Vrain. One portion of our review concerns the systems which are being relied upon to provide safe shutdown (Trains A and B for noncongested cable area fires and the ACM components for congested cable area fires).

Our initial review disclosed certain deficiencies in the submitted information which were discussed with your staff during a telephone conference on October 17, 1985.

The questions raised during this conference call and questions related to manual operations and instrumentation are listed in the enclosure to this letter. Additional questions may be developed as a result of our continued review or from your responses to these initial questions.

We request that you provide a response to these questions within 30 days of your receipt of this letter.

The information requested in this letter affects fewer than 10 respondents; therefore, OMB clearance is not required under P.L.96-511.

Sincerely, Edward J. Butcher, Acting Chief Division of Licensing Office of Nuclear Reactor Regulation

Enclosure:

Fort St. Vrain Fire Distribution: Docket! File' Protection Review Questions NRC & L PDRs KHeitner PKreutzer PWagner cc w/ enclosure: RIreland DKubicki See next page JStang Olynch BGrimes y ORB L HBerkow Branch Files EJordan ORB #3: ORB #3:DL KHeitner;ef EB ter ACRS 10 OELD P(reu er

-\ r /05 no /3 /85 /0/ /85 8511250332 851101 PDR ADOCK 05000267 F PDR

• 4 Mr. O. R. Lee Public Service Company of Colorado Fort St. Vrain cc:

C. K. Millen Albert J. Hazle, Director Senior Vice President Radiation Control Division Public Service Company 4210 East lith Avenue of Colorado Denver, Colorado 80220 P. O. Box 840 Denver, Colorado 80201 J. W. Gahm Nuclear Production Manager Mr. David Alberstein,14/159A Public Service Company of Colorado GA Technologies Inc. P. O. Box 368 P. O. Box 840 Platteville, Colorado 80651 Denver, Colorado 80201 J. K. Fuller, Vice President Public Service Company of Colorado P. O. Box 840 Denver, Colorado 80201-Senior Resident Inspector U.S. Nuclear Regulatory Commission P. 0. Box 640 Platteville, Colorado 80651 Kelley, Stansfield & 0'Donnell Public Service Company Building Room 900 550 15th Street Denver, Colorado 80202 Regional Administrator, Region IV U.S. Nuclear Regulatory Commission Office of Executive Director for Operations 611 Ryan Plaza Drive, Suite 1000

. Arlington, Texas 76011 Chairman, Board of County Commissioners of Weld County, Colorado Greeley, Colorado 80631 Regional Representative Radiation Programs Environmental Protection Agency 1800 Lincoln Street Denver, Colorado 80651 l

1

Enclosure Fort St. Vrain Fire Protection Review Questions .

1. There are situations in which a single failure can defeat a function comon to both trains proposed for forced circulation safe shutdown.

a .'

The service water strainer (F-4201) and the associated flow valves (HV-4257. HV-4225 HV-4221-1, and HV-4221-3) are required to be operated in both proposed trains. What provisions have been made to provide for continued system function if a fire disables or precludes positioning of these components?

b. Have all other situations where single failures could disable the function been evaluated?

2. Review of the Tables contained in Section 2.1 of Report 1 (as revised) shows that not all of the required valves are listed.

a. What criteria was used to determine if a component should be incicded in the Table? (e.g., Table 2.1-3, sheet 3 of 5 lists V75595 to be closed but does not indicate that parallel valves V75600 and V75605 would need to also be closed; also, other valves off the same line would need to be properly positioned but are' not listed.) -

b. Do the implementing procedures require checking the position of 'al'1 valves in the flow path? (e.g., A valve in the flow path that is designed to fail close and is required to be close should be r verified to be closed; HV-2223 should be verified closed.)

3. The condensate storage tank is common to both safe shutdown trains.

a. ,What is the minimum storage capacity necessary to complete the assumedfunction(s).

• ' b. This minimum capacity should be incorporated as a Technical Specification limit, as should all equipment for which credit is taken in the shutdown models.

4.- The shutdown models for forced circulation cooldown, for a fire in a noncongested cable area, do not contain provisions for maintaining PCRV

liner cooling. In light of the acceptance criteria B.2.b. contained in the PSC letter dated August 17, 1984, provide an evaluation of the

-necessity of maintaining liner cooling.

5. Provide an evaluation of the need of a main cooling tower fan in safe shutdown model Train B.

6. A list of required ACM fire protection shutdown components is provided in Table 3.2 of Report 1.

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a. Provide a listing of the equipment identification numbers and the normal power supplies for these components.

b. Provide a description of all changes made to the "ACM shutdown system" since its use was approved in License Amendments Nos. 14, 18, and 21.

7. Drawing PI 31-1 shows a removable spoolpiece between the fire water system and the line from the main feedwater pumps.

a. Is this spoolpiece normally installed? If not, describe how its storage and installation are controlled. (In similar applications at other facilities, the spoolpiece is a Technical Specification controlleditem.)

b. Describe all other spoolpieces which are being used in the shutdown models and the controls used.

8. Since provisions are not included in the shutdown models for its operation, provide an evaluation of the necessity of the Buffer Helium System for circulator operation.

9. The shutdown models for forced circulation cooldown consist of providin'g cooling water to the economizer-evaporator-superheater section of one of the steam generators via a low-pressure pump (condensate or fire water).

Since the steam generators will be at relatively high temperatures (greater than 1000*F at shutdown) and are helical wound tubes with no storage capacity, provide an evaluation of the effectiveness of this mode of cooldown. This evaluation should include a study of the possibility of damage, caused by occurrences such as water hammer or over pressurization, during such a cooldown.

10. The capacity of the diesel firewater pump is indicated on drawing PI-45 to be 1500 gpm; Figure 2.1-9 of Report 1 indicates that this pump will provide 155 gpm for a Helium Circulator and 1050 gpm for a steam generator. Provide an evaluation which verifies that adequate capacity is available to perform the safe shutdown functions in addition to providing sufficient fire suppression water flow.

11. Provide a description of the testing program which will be implemented to verify the operability of the proposed safe shutdown models.

12. There are numerous operations contained in the Tables of Section 2.1 of Report I which require the operator to "De-energize and open or close" manually (HV-3133-1 and HV-3133-2 in Table 2.1-3) or " Remove power and open or close" locally (HV-4221-2 of Table 2.1-6). Operations such as removing fuses and, in most cases, opening power supply circuit breakers are considered repair operations and are not allowable for the train required for hot shutdown (III.G.1).

Provide a description of what actions are ne.cessary to accomplish the I operations indicated in the Tables of Section 2.1 along with an evaluation of the time required to perform these actions.

13. Provide an evaluation that the Technical Specification required, onshift, crew size is sufficient to perform the actions proposed for the various shutdown models without reliance on Fire Brigade members.

14. It is the staff's position that monitoring of core flux provides the only direct indication of the reactor shutdown condition and therefore provisions for postfire source range flux monitoring are necessary to meet Section III.L.2 of Appendix R and, therefore, A.3.a. and B.2.b. of the PSC letter dated August 17, 1984. The position stated in Section 2.3 of Report 1, that, since a fire cannot credibly prevent control rod insertion, neutron flux monitoring is not required, has not been adequately justified. Include source range (startup channels)monitoring provisionsorinprovide all shutdown an evaluation models for of alternatives available to monitor core reactivity conditions. .,

.15. Provide an explanation of how the reactor decay heat removal function will be monitored following a fire in a noncongested cable, area (Criteria, -

B.2.c. and d.) without maintaining Primary Helium temperature instrumentation operable.

16. Provide an explanation of how the reactor pressure control function will be monitored for a fire in a congested cable area (Criteria A.3.b. and d.) without maintaining Primary Helium pressure instrumentation operable.

. n.

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