IR 05000312/1986031

Insp Rept 50-312/86-31 on 860729-31.No Violations Noted. Major Areas Inspected:Meteorology Program

ML20211B354
Person / Time
Site:	Rancho Seco
Issue date:	09/26/1986
From:	Fish R, Prendergast K NRC OFFICE OF INSPECTION & ENFORCEMENT (IE REGION V)
To:
Shared Package
ML20211B352	List: IR 05000312/1986031 ML20211B346
References
50-312-86-31, TAC-63085, NUDOCS 8610170217
Download: ML20211B354 (4)

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bs U. S. NUCLEAR REGULATORY COMMISSION

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REGION V

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Report

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No. 50-312/86-31

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Docket No. 50-312

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l Licensee: Sacramento Municipal Utility District

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,P.,O. Box 15830 .

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Facility Name: Rancho Seco Nuclear Generating Station

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Inspect:fon -atil l Clay Station

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. Inspection Conducted: July 29-31, 1986-b hb -

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Inspector: A

K. M. Prendergast # Date Signed Emergency Preparednans Analyst ,

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- ; Team Member: Irwin Spickler, Meteorologist, NRC Approved By:

R. F.' Fish, Chief A 7h6 [I D4te. Signed Emergency Preparedness Section Summary Inspection on July 29-31, 1986 (Report No. 50-312/86-31).

Areas Inspected: Routine followup inspection of the licensee's meteorology progra Inspection procedure 92701 was use Results: No violations of NRC requirements were identifie _ - ... .. . . . _ . . , ,

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DETAILS ,

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,L Coward Plant Manager

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w" . *R.- Ashley, Manager, Nuclear Licensing -

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[ , , . '.*DL Martin,; Director Emergency Planning , ;- 1 >

• E.'Eik_ horn,' Emergency Planner

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. - *M.;Hardin, Engineering Specialist,.I:and C Maintenance ,

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• R. Meyers, Supervising Emergency Planner"

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/ '* Indicates attendance at the exit intervie + J '

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Followup On the Meteorology. Program

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' r The report (no. - 50-312/85-05) of-the February 1985; inspection contained a ,

historical review of' problems identified.in'the licensee's meteorological

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. measurements program (MMP) and corrective actions to resolve them. NRC-inspection report no. 50-312/85-35, performed in December of 1985, documented improvements to the meteorology system; however, problems with the delta. temperature instrumentation still existed. This inspection was performed to determine the status of the' licensee's corrective actions to satisfactorily; resolve problems identified in the MM ,

. In an effort to' determine the status of improvements to the MMP, records

.of daily'and quarterly instrumentation checks were reviewed, and-discussions with'th~e licensee's consulting meteorologist and the SMUD-staff ~ responsible for_the meteorological instrumentation were held. :In addition, a review'of the NRC Technical Evaluation Report which included an evaluation of site meteorological data from October 1985 to May 1986,

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was performed. The results of this inspection indicate, the licensee:ha made many modifications.to the MMP'at the~ Rancho.'Seco site which have- '

improved the quality.of~the program.' However, based.upon the results of this insp'ection and the analysis of data collected on-site from October 25, 1985 to May 30,.1986.and submitted to the NRC for review, the following suggestio.ns for improving the MMP should be evaluated in the

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light of insuring adequate meteorological capabilities are presen Resolve the differences between the two thermal gradient measurement

systems. The vertical temperature gradient (atmosphere stability)

is a key parameter needed to estimate the potential diffusion of

releases. It is used to determine the growth of an effluent plume

. with distance. The' January 1986 NRC Technical Evaluation Report i' '

(TER), and NRC inspection report 50-312/85-35 both' indicate inconsistencies in the temperature measurements made by the-

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duplicate ' systems at both the 10 and 60 meter levels. The licensee i- , 'has moved the sensors closer to one another, changed the aspirator L ' shields arid on June 15, 1986' installed four new matched sensors.

However,'the two ten meter' sensors still appear to be~ inconsistent during'the day. Based upon the'results of this inspection,<further

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effort is still required to obtain a better agreement between the .

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stabilit a

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, The; licensee's present calibration system for'thd meteorol'ogical sensors'needs to be. improved by instituting wind tunnel calibration-of the wind > speed.and' direction sensor systems. The wind sensors-

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are calibrated semiannually on the tower.. The. anemometer accuracy b , is only tested at one.high wind speed using a rotary device.. The

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vanes are turned manually to a surveyed direction and the wind '

directions then recorded,are examined. The. system electronics are i - checked and calibrated. The bearings are changed when some:

- - istanceLto hand movement is felt during the course:of. calibration

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'_ or- some other maintenance activities.. < -Otherwise, the wind tunnel - ,

calibration'eurves that were provided by the manufact'urer at the

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time.of installation are'used. The problems with the present method- ,

t ' of calibration are that the wind speed and direction measurements ,

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willu hange c with' time due to wear of the b' earings, dirt lodging:on ~

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the bearings and wear of the: anemometer cup's and vanes. Without.the' '

' assurance of_a regular wind tunnel calibration, possible

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Inaccuracies ^ in the wind directionand sp'ee'd measurements could lead'

to an inaccurate. assessment:of; diffusion and transport'of

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. accidentally released effluents.- -  %,

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, ;?, In addition to establishing an' improved calibration' program for

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meteorological. sensors, the licensee should' insure.that: bearings are

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changed on regular basis to_ insure accurac '

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, c.- In order to. assure that quality-meteorological data are available

- when needed~in an emergency. situation, the; quality control program

should be improved in the following_ areas:

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1) Provide formal training for the plant meteorological instrument-

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technician' including; instrument mechanics,' instrument theory-F and rudimentary meteorological theory.

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-ii)- Develop a quality assurance documentation manual which ~ ~

, completely lays out tracking for meteorological instrument ,

j^ maintenance, modification and calibratio iii) Iinprove the present on line computer meteorological data .

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. editing program. The licensee has a program which will prevent t .'the input of erroneous meteorological data in the emergency.

I response dose assessment, however some erroneous' data was still'

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allowed'into the meteorlogical informaticn bank.' The' licensee should review this area to ascertain if further improvements are

necessary.

E iv) Consider including the MMP in.the Systeme Engineer Progra Evaluate the adequacy of the lightning protection system currentl in place on the' meteorological station. tower. The present' surge

, protection may not be able to adequately protect.the meteorological instrumentation should the tower be struck by lightnin ' 6

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Based upon the;results of this portion of the inspection, the licensee

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hae made considerable improvements in the quality of the meteorological data, however further. improvements appear appropriate (0 pen Item, 84-11-03).

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No violations of NRC requirements or deficiencies were identified in the review of this program are . Dose Projection-A review of the licensee's methods to assess the impact of a release of radioactive materials to the environment was performed.~ Based upon this review, the licensee should consider incorporating a time and space variable model into the emergency response dose assessment capabilit Appendix E to 10 CFR 50 requires that a power reactor licensee have the capability, on a real-time basis, to be able to realistically assess the

' potential consequences of reactor accidents.. At the present time the-licensee has incorporated only a straight-line diffusion model with the same diffusion conditions existing between the_ source and each of the receptors in the emergency response dose assessment model. While this -

straight-line diffusion model approach nay be appropriate for some reactor sites, it is not for Rancho Seco because, as stated in the August .

1981 report of a meteorological review performed for SMUD by Energy Resources Company, the site is " roughly" .cn1 the divergence line that lies between Sccramento and Stockton. Sacramento and Stockton. located north and south of the site respectively, exhibit differing airflow pattern In addition, according to this aame report, the " impact of the foothills of the Sierra Nevada represents an important aspect of.the wind flow characteristics of the Rancho Seco area." Thus, it can be concluded that the' straight-line diffusion model may not provide the licensee with a realistic assessment of plume trave No violations of NRC requirements or deficiencies were identified in the review of this program are . Exit Interview An exit interview was held on July 31, 1986 for the purpose of discussing the preliminary findings of this inspection. Licensee personnel present have.been previously identified in paragraph I above. Glen Perez, Acting Senior Resident Inspector, was also present. The licensee was informed that no violations of NRC requirements were identified within the scope of this inspectio Items discussed during this meeting are identified in paragraphs 2 and 3 above. The licensee's improvements to the MMP were acknowledge However, further improvements are recommended to insure an adequate meteorological measurements program is availabl .

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