ML20236K477

Special Rept 87-21:on 870929,deluge Sys for Zone 81 Not Returned to Operable Status within 14 Days.Caused by Delay in Required Matl Procurement.Fire Watch Established for Inoperable Sys Per Tech Spec 3.14.3.2

ML20236K477
Person / Time
Site:	Rancho Seco
Issue date:	10/29/1987
From:	Firlit J SACRAMENTO MUNICIPAL UTILITY DISTRICT
To:	Martin J NRC OFFICE OF INSPECTION & ENFORCEMENT (IE REGION V)
References
87-21, AGM-NPP-87-329, NUDOCS 8711090238
Download: ML20236K477 (2)

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1 IS suun SACRAMENTO MUNICIPAL UTILITY OlSTRICT O P. O. Box 15830, Sacramento CA 95852-1830,(916) 452-3211 AN ELECTRIC SYSTEM SERVING THE HEART OF CALIFORNIA AGM/NPP87-329 DCT b 91987 U. S. Nuclear Regulatory Commission m Attn: J. B. Martin, Regional Administrator 23 Region V a Office of Inspection and Enforcement S, O - ,

1450 Maria Lane, Suite 210 .5 w as Halnut Creek, CA 94596 d J!y 5 G O' DOCKET NO. 50-312 RANCHO SECO NUCLEAR GENERATING STATION $ '

LICENSE NO. DPR-54 .

SPECIAL REPORT 87-21: ISOLATION OF ZONE 81 DELUGE SYSTEM i

Dear Mr. Martin:

The deluge system for Zone 81 was not returned to . operable status within the 14 days specified in the Rancho Seco Technical Specifications. Thus, in accordance with Technical Specifications 3.14.3.2 and 6.9.5.2, the Sacramento Municipal Utility District hereby submits Special Report 87-21 describing the problem and actions taken.

Please contact me if you have any questions. Members of your staff with questions requiring additional information or clarification may contact Kurt i Zimmermann at (916) 452-3211 extension 4627.  !

Sincerely,

( ., .J h ja sep F. Firlit Assistant General Manager, Nuclear Power Production Attachment cc: G. Kalman, NRC, Bethesda (w/atch)

A. D'Angelo. NRC, Rancho Seco ( " )

F. J. Miraglia, NRR, Bethesda ( "

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0711090238 871029 PDR s

ADOCK 05000312 PDR.

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R.ANCHo SECO NUCLEAR GENERATING STATION O 1444o Twin Cities Road, Herald, CA 95638-9799;(209) 333 2935

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SPECIAL REPORT NUMBER 87-21.  ;

ISOLATION OF ZONE 81 DELUGE SYSTEM J

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'Date'of Reoort:  ;

October 29, 1987 1

Date of Occurrence:

September 29, 1987

' Plant Conditions Prior to Occurrence: ,

The plant has been in a major outage with the reactor in cold shut' down.

Identification of Occurrence 1

'The deluge system for Zone'81 (east cable shaft of the Nuclear Service Electrical Building) was not returned to operable status within 14 days as .

I specified in Technical Specification 3.14.3.2.

Description of Occurrence:

On September 15, 1987, the~ deluge system for Zone 81 was isolated in order to replace damaged spray nozzles. A delay in required material procurement produc2d a delay'in work.  !

Corrective Actions Taken:

A fire ratch was established for the inoperable system in accordance with Technical Specification 3.14.3.2. The system was restored to operable status on October 6,1987 upon completion of the required spray nozzle replacement.

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~ - SACRAMENTO MUNICIPAL UTILITY DISTRICT C P. o. Box 15830, Sacramento CA 95852 1830,(916) 452 3211 i AN ELECTRIC SYSTEM SERVING THE HEART OF CALIFORNIA l OCT 2 9 sy GCA 87-733 1

U. S. Nuclear Regulatory Commission Attn: Frank J. Miraglia, Jr.

Associate Director of. Projects j!

Philips Building l 7920 Norfolk Avenue )

Bethesda, MD 20014 l l

Docket 50-312 l Rancho Seco Nuclear Generating Station Unit No. 1 License No. DRR-54 l R

Meterological System Program Improvements l

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Dear Mr. Miraglia:

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I On February 26, 1987, in letter JEW 87-228 from J. E. Ward (SMUD) to Mr. Frank Miraglia (NRC), the District identified numerous '

i meterological system and program improvements intended for comp.letion prior tg restart. A majority of these commitments are well on their way bb completion, j

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g flowever, item No. 5 of' Attachment B to letter JEW 87-228, cannot be directly addressed based on our present knowledge of the divergence zone meterological flow phenomenon. This item I indicates that SMUD will issue a purchase order for a Class "B" meteorology'model. In order to evaluate which industry available models are most applicable to the unique meteorological flows at Rancho Seco, SMUD needs to identify the specific nature of these flows from existing studies, and eventually from its own field study. Therefore, the District wishes to rescope its approach to item No. 5 of Attachment B.

The District's approach prior'to restart will be as follows:

1. Examine existing literature on the divergence zone meterological phenomenon to broadly assess the uncertainty in the dose projection results of the j existing Class A straight-line Gauss'ian model.  !

2. Modify the existing Emergency Plan and affected j implementing procedures to modify Protective Action l Recommendations to compensate'for the identified I uncertainties. l l

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RANCHO SECO NUCLEAR GENERATING STATION 14440 T win Cities Road. Herald C A 95638 9799;(209) 333 2935

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FRANK J. MIRAGLIA, JR. GCA 87-733

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, The' District' proposes to accomplish the following activities after restart to'further address the dose projection uncertainties' introduced by the divergence zone phenomenon:

3. . Modify the existing'. class A.model to calculate dry. l' deposition using a conservative deposition velocity of O.01 meter /second. {

4 i 4. Perform a field study.during a temporally ,

i representative portion of the divergence zone. period 1 I

(i.e., May to September 1988), utilizing ccncurrent

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data obtained from.several 10-meter meteorological-towers located at strategic positions east of Rancho Seco to betterJdefine. divergence zone flows.

5. Based on the study.results, enhance existing class A model by developing site-specific adjustments to better address divergence zone flows.

6. Modify the prior'to restart compensatory protective. q actions to be consistent with the enhanced class A  !

Model capability.

Prior to the commencement of the field study, the District wishes to meet with cogniihnt NRC individuals to review the field study -l protocol with respect.to the optimum number and location of the I g

study towers.

The. resolution of items 3 through 6 after restart will not affect the health and safety of the public because the necessary equipment to implement the Rancho Seco Emergency Plan will be operational at restart.

Please contact me if you have any comments or questions. Members of your' staff, with comments or questions requiring additional information or clarification, may contact Mr. David Compton at extension 4915.

Sincerely, i , ,

/rd'&,if,An

. 'Ca a<

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' Chief Exec tive Officer, Nuclear 1 l

cc: G. Kalman, NRC Bethesda (2) l A. D'Angelo, NRC Rancho Seco i I. Spickler, NRC Bethesda R. Fish, NRC, Region V, Walnut Creek  !

J.-Martin, NRC Region V, Walnut Creek i l

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