ML20202G670

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Forwards T Loffman 851114 & 860701 Memos to R Myers Re Plant Meteorology Program,Per 860528 Request for Addl Info.Data Tape Request Sent Under Separate Cover Ltr
ML20202G670
Person / Time
Site: Rancho Seco
Issue date: 07/10/1986
From: Julie Ward
SACRAMENTO MUNICIPAL UTILITY DISTRICT
To: Stolz J
Office of Nuclear Reactor Regulation
References
JEW-86-204, NUDOCS 8607160050
Download: ML20202G670 (12)


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SACRAMENTO MUNICIPAL UTILITY DISTRICT T P. O. Box 15830, Sacramento CA 95852-1830,(916) 452-3211 AN ELECTRIC SYSTEM SERVING THE HEART OF CALIFORNIA July 10,1986 JEW 86-204 DIRECTOR OF NUCLEAR REACTOR REGULATION ATTN JOHN F STOLZ DIVISION OF PWR LICENSING-B PWR PROJECT DIRECTORATE #6 U S NUCLEAR REGULATORY COMMISSION WASHINGTON DC 20555 RANCHO SEC0 METEOROLOGY PROGRAM This letter provides the additional information requested in your letter dated May 28, 1986.

Item 1 of your request is discussed in detail within two memoranda (enclosed) from the District's consulting meteorologist to the Meteorological Coordinator. The data tape requested in Item 2 was sent under separate cover letter (to Sydney Miner, Project Manager) dated June 2, 1986.

District staff has been informed of an announced inspection of the meteo-rological program during the last week of July. My staff looks forward to the opportunity to review this and other pertinent information with the inspectors at that time.

Meanwhile, if the District can answer any questions regarding this sub-mittal, please call Robert Myers at (916) 732-6025.

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f JOHN E. WARD ASSISTANT GENERAL MANAGER, NUCLEAR (ACTING)

Enclosures cc: Ray Fish, NRC Region V w/ attachments 0607160050 060710 PDR ADOCK 05000312 PDR F

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DISTRICT HEADQUARTERS O 6201 S Street, Sacramento CA 95817-1899

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a TO:

R08 MYERS l

i FROM:

TOM LOFFMAN - CONSULTING METEOROLOGIST

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RE:

RANCHO SECO METEOROLOGICAL PROGRAM PROGRESS REPORT DATE:

NOV. 14, 1985 i

ABSTRACT During the Spring of this year the Department Managers of the

" Nuclear Family" at Rancho Seco directed that a Task Force be set up to bring the meteorological program up to compliance with Industry standards.

One of the major recommendations of the Task Force report issued April 15, 1985 was the hiring of a Meteorologist to determine the 4

validity of the meteorological data from Rancho Seco.

I was hired as the meteorological consultant in August. My initial evaluation of the meteorological data and system at Rancho Seco lead me to conclude that there had been and still were some questions about the validity of the data.

I then began to work uith SMUD personnel and contracted staff at Rancho Seco with the following objectives:

1. Determine the current status and condition of the meteorolo-gical data Z. Trace down the possible causes of the problems t
3. Identify the persons responsible for making the corrective i

changes in the data gathering process

4. Monitor and coordinate the corrective procedures
5. Reconnend techniques and procedures for future data validation i

As of this writing I an able to report that items one, two and three have been completed. Iten four is nearing completion, and iten five is in progress.

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With respect to the current validity of the data I can say that a i

number of corrective actions have been taken and the accuracy of the 9

data now being obtained from the meteorological systen has been significantly improved. Only one minor problem remains. After the last problem has been corrected the task will then be to continue to monitor j

and evaluate the data over the course of the coming year to make sure that the data validity remains stable through all types of weather

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conditions.

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CURRENT METEOROLOGICAL SYSTEM AT RANCHO SECO The current systen of meteorological instrumentation at Rancho Seco meets or exceeds all NRC requirements in its present configuration.

However, the data that has been obtained from the j

instruments has not always met with requirements. In particular, the recent GA Audit noted deficiencies in the Delta T accuracy, and questioned the accuracy of the primary channel temperature instruments.

based on comparison with the backup temperature instruments.

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Determining the validity of primary channel temperature measure-ments by cross-checking with backup instruments far exceeds any NRC regulation, and is not standard practice at other Nuclear facilities in this country. However, since the primary end backup instruments on the meteorological tower at Rancho Seco are placed very close to each other l

a cross-comparison cannot be avoided. Once the last instrument prob-lem has been solved the Rancho Seco setup will be a MODEL of data l

j accuracy and validity - far exceeding the exacting requirements of the Regulatory Guide specifications outlined in the QA Audit.

l CAUSES OF THE PROBLEMS WITH THE METEOROLOGICAL DATA The history of and problems uith the meteorological instruments and their current status is detailed in the November 1,1985 of fice memorandum written by I&C Technician Mike Hardin (see attached). During the past year the I&C department has been working steadily on f

determining the system problems, and has successfully taken a number of steps to correct those problems. To date, most of the problems have been solved, and from a review of the data now being displayed on the IDA03 screens in the Technical Support Center (TSC), it appears as if the Delta T readings are both stable and valid. It is the hope and expectation of all involved that this data u111 remain stable and valid as we progress into the Winter cold and will hold in that condition through the heat of the Summer.

The final problem that needs to be solved for absolute certainty of accuracy is the consistent matching of primary and backup channel temperature measurements - and as mentioned previously, this is not a requirement of the NRC, but is a technique used by me and by I&C to determine absolute temperature accuracy.

At present, ue are awaiting the installation of a set of four matched temperature sensors by Qualimetries/ Weather Measure. I know of no other Nuclear f acility where this has been done. Once this has been completed, the temperatures obtained from the Rancho Seco tower should be the most accurate in the country.

In addition to the instrument accuracy problems, deficiencies were found in the MIDAS software by Realogic consultant Bob Bass. To date, i

these deficiencies have been corrected. It is not known whether these deficiencies have been noted and corrected by other Nuclear facilities that use the MIDAS software package, but we are confident, after exten-sive testing, ~that our MIDAS sof tware is displaying the meteorological data without error.

PERSONS INVOLVED IN THE CORRECTIVE ACTIONS The key individuals involved in making the corrective changes in the system are the I&C technicians and the Realogic consultants. My efforts have been directed toward identifying and coordinating these activities in a way that keeps then moving in the desired direction. I have also attempted to establish lines of communication between all persons involved in the problem solving activities. To date, I believe that all concerned individuals in these corrective actioas are l

communicating and work ing together in a cooperative and concerted ef fort to maintain the integrity of the system.

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TECHNIQUES AND PROCEDURES FOR DATA VALIDATION One of the first discoveries I made was that the meteorological data was not readily available in a form that made data validation a simple and ef f ective task. A meeting was held with representatives of the I&C department, the QA Audit department and Realogic, and a program was outlined f or a MIDAS task that would print out the data in the needed f ormat. Details of this meeting are described in the QA Assurance Surveillance Activities Report issued Nov.

I, 1985.

Once this progran is inplemented, data validation will become a very straight-foreward procedure, and it will be possible for all concerned individuals to check the data for possible problems.

Until this program is implemented, however, data validation will remain a slow and arduous procedure.

OVERALL OBSERVATIONS ON CURRCNT PROGRESS My overall observation is that progress is being made rapidly to insure compliance with all NRC requirements. Indeed, we will exceed those requirements and should attain a level of accuracy that will be difficult to match in the industry. I en pleased that progress has been very rapid, and all individuals involved are making significant gains toward the desired obj ectives. I an confident that we are headed in +5e right direction.

Another area that deserves attention, besides the instrumentation, is the NRC requirement for a backup source of data in the event of a failure of the instrument tower.

It had been assumed, that backup weather information could be obtained from the National Weather Service via a telephone call to their offices. It has been my experience that the National Weather Service is difficult, if not impossible to contact during times of severe weather. The reason for this is the limited personnel available at the National Weather Service and the needs of that personnel to handle their assigned duties rather than to answer the telephone.

I an recommending that the most reliable way to cbtain backup neteorological data is through a private, computerized weather data base ( such as Weather Services International, Bedf ord, Mass. ) and accessed via computer using a moden and communications software. This backup equipment should be available both in the Technical Support Center at Rancho Seco and at the EOF (Energency Operations Facility).

PROGRESS TOWARD COMPLETION OF TASK FORCE REPORT RECOMMENDATIONS In reviewing the Task Force report I find that significant progress has been made in implementing the recommendations.

Specifically:

1. PROGRAM COORDINAYOR: While a permanent coordinator has not yet been selected, we are making significant progress and functioning well under Rob Myers, our Interin Coordinator.
2. METEOROLOGIST: Since I have been under contract as consulting

P Meteorologist this reconnendation has been fulfilled.

3. MULTIPLE SOURCES: Primary and backup instruments are located on the meteorological tower side by side and hence comparisons of the instrument readings are unavoidable. Data validation using this technique, however, is not a requirement of the NRC. However. we are getting a set of f our matched temperature sensors and we expect all f our sensors to cross verif y. Presently, accuracy and validity of single channel data is excellent and meets all NRC requirements. Our only task in that regard is to monitor the validity through the seasons.
4. Number 4 was not listed in the Task Force Report
5. DATA EVALUATION PROCEDURE: Progress is being made on a MIDAS task to print out the data in a format that will allou evaluations of the data for accuracy and validity. The needs of all persons involved in the monitoring have been provided for.

G. QA AUDIT: The OA Department performed an audit of the meteorological program on Oct. 11, 1985. Additional audits are scheduled.

7. DELTA T AND DUAL INSTRUMENTATION: As a result of the corrective actions by I&C and Realogic, the Delta T neasurements have been valid for both primary and backup channels for several weeks. It appears those problems have been solved. As has been mentioned previously. the dual instrumentation at Rancho Seco is not connon in the industry, and cross validation is not a requirement for NRC compliance.
8. DATA INTERPRETATION: With the meteorological consultant nou on staff, the program of data interpretation is now on going. This process will be greatly enhanced once the MIDAS data progran to. facilitate this is completed.
9. PRECIPITATION INS 1AUMENTATION: Precipitation measuring equipment is now in place. and data is coming into the plant computer system. Further work needs to be done by Realogic to convert the data.

to a usable format that meets NRC requirements.

10. MIDAS AVERAGING: Completed by Realogic.
11. ANATEC MULTIPLEXER: Completed by I&C.
12. PORTABLE INSTRUMENTS: These instruments were shown to the NRC and we were in agreenent on their limitations. My reconnendations for obtaining backup neteorological data using a moden-based systen were described previously. The reconnended backup systen should totally replace the portable instruments.

i ROLE OF THE CONSULTING METEOROLOGIST Since September I have taken an active role in the evaluation, and coordination of the activities involved in correcting the deficiencies of the mateorological progran at Rancho Seco. Once these problems have been solved an evaluation of the role of the consulting neteorologist uill have to be made by the Meteorological Progran Coordinator.

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Until that time, however, I expect to continue to monitor the progress of the corrective activities. We are presently awaiting the new temperature sensors, and once they are in operation a re-evaluation of the Delta T and system validity will have to be made. Further, the data will have to be checked under various weather conditions to insure that the validity will stand up under extremes of temperature, cloudiness and wind.

Further tasks are: the integration of the precipitation readings into the data base, and evaluating the new MIDAS meteorological data analysis program.

CONCLUSIONS Af ter a complete review of the meteorological program and instrumentation, I am pleased that significant progress has been made and is being made toward correcting all existing problems, meeting the Task Force recommendations, and providing for future data validation.

Thanks to the concerted efforts of the capable people who have been concentrating their efforts toward solving the problems of the past, we are nearing a point where the meteorological system at Rancho Seco is meeting all NRC requirements, is providing accurate and valid data, is meeting the needs of all persons involved in the program, and will be a MODEL of data accuracy and validity for the Nuclear Industry.

The problems are being solved rapidly, communication between the working members of the program is excellent, and progress toward the remaining objectives is proceeding in a timely manner.

I am pleased with where we are, and where we are headed.

TOM LOFFMAN METEOROLOGIST NOVEMBER 14, 1985 l

TO:

ROB MYERS FROM:

TOM LOFFMAN CONSULTING NETEOROLOGIST RE:

RANCHO SECO METEOROLOGY PROGRAM DATE:

JULY 1, 1986 OVERVIEW The Technical Evaluation Report on Rancho Seco meteorological data, prepared by the Pacific Northwest Laboratories, provides a valuabl e look at the state of the meteorological gram at Rancho Seco prior to our efforts over the past year and a he' In the NRC letter to SMUD dated May 28, 1985 a request is made to document the methods utilized to determine past problems, and the measures taken to correct the problems, and prevent further occurrence.

Much of this information has already been documented by me in my letter of Nov. 14, 1985. Therefore, I have attached a copy of that letter,

and will attempt, in this letter, to address certain points mentioned in the lab report, and bring all concerned up to date on the current status of the meteorological data program at Rancho Seco.

COMMENTS ON COMPARATIVE DATA The Rancho Seco data for 1984 was compared with the data for the Sacramento Executive Airport for 1984, and with historical data from that location.

Although it is the nearest complete data source available, there are two problems with the Executive Airport data that should be noted.

First, I have worked with that data on a real-time, daily basis since 1978 and have found numerous, and from my perspective, rather serious inconsistencies in the temperature reports from there. For weeks or months on end the airport will show temperatures running consistently belou others in the area. Then, without notice, this will be changed, only to switch around again some weeks or months later. I have called the National Weather Service when this has occurred and found out that calibrations were made at the tines when the data changed.

I am becoming convinced after observing these problems and similar problems which have occurred in the past at Rancho Seco that calibrating meteorological sensors, rather than being a straight-foreward procedure, is more of an art, and indeed a delicate art that must be mastered with care, rather than merely performed in a perfunctory manner. In f act, the problems which remain in the Rancho Seco data today can be traced to points in time when the data "shif ted" 1

af ter or during a calibration by Qualimetrics/ Weather Measure (Q/WM).

Based on my experience with the Executive Airport data set, I do not

have a great deal of confidence in that data for precision monitoring of the Rancho Seco data set. I believe the historical data set is more instructive, since, at least theoretically, it integrates enough years of information that the inconsistencies noted earlier are somewhat smoothed out.

Secondly, the micro-climate of the Executive Airport is, in many rather critical ways, quite different from Rancho Seco.

Many of the inconsistencies noted in the lab report can be easily explained by this difference in micro-climates. I will be addressing this later in this report.

Additionally, the lab report in section 1.0 noted that "The 1984 data were found to lie within the climatological extremes and did not show any anomalous tendencies."

While the 1984 data set was stated in the report to be within historical limits, 1984 was anomalous in that the summer was one of the hottest on record.

In fect, the total number of " cooling degree days" recorded that summer was an all-time record.

We experienced a high number of days when the usual sea-breeze pattern was absent, and upper atmospheric inversions were common. In my discussions with the NRC and others who have monitored out program it has been a common problem that our local scale climatology is not well understood, particularly the sea-breeze regime, the inversion problem, and the wind divergences that occur here.

NOTES ON THE SINGLE TOWER PROBLEM As noted in the lab report section 2.0 the Rancho Seco instruments are located on a single tower. Not mentioned in the report was the fact that this configuration is highly unusual for a Nuclear facility - in fact, almost unique in this country.

As noted in previous QA Audits, and in my report of Nov.

14, 1985

( at t ached) cross checking both primary and backup sensors is not a requirement of the NRC, and yet it is precisely this cross checking that has allowed us to spot inconsistencies in the data and calibrations.

If the primary and backup instruments had been placed on separate towers, as is done almost everywhere else, it is possible that many of the MORE St'9TLE calibration problems would have gone unnoticed.

I am seriously concerned that data inconsistencies being noted by other facilities is being dismissed under the blanket of " micro-climatic" differences between the towers.

The lab report on the Rancho Seco data tests the 1984 data set against Airport data and records and essentially passes data that appears to be "in the ballpark". Such a comparison cannot detect SUBTLE errors. See section Lab Report section 3.0.

The reason these " subtle" errors are so important is because the NRC requirements for Delta T are quite stringent.

Unless other facilities are cross correlating their Delta T data there is no way that these minute calibration errors can be detected.

It is entirely possible, and I suspect probable, that if other f acilities had their instruments positioned all together on single towers, that many more problems would be detected that are nou going unnoticed.

STOCKTON COMPARATIVE DATA The Lab Report noted problems with obtaining a continuous set of data from the Stockton Airport. I have not noticed this problem, and have been able to call up complete data sets from Stockton for my forecasting work. I did, however, notice a marked dounuard shift in temperatures being sent from Stockton this year.

In previcus years, I received a number of complaints from the Stockton Chamber of Commerce about the Stockton temperatures being reported as too high. I consistently referred them to the National Weather Service.

This year, the temperatures we receive from Stockton are consistently lower than surrounding areas. Since the City of Stockton hasn't been physically altered to accommodate this wide suing in temperature I suspect that the sensors at the Stockton Airport have been adj ust ed dounuard to please the Chamber of Commerce. This brings be back to a previous statement that the calibration procedures used to adjust these airport sensors is highly suspect.

and I view the data with that in mind.

RESPONSE TO SPECIFIC NOTED PROBLEMS The Lab Report notes inconsistencies throughout the Rancho Data set.

The list of problems covers most areas of data collection, with certain areas standing out more than others.

Before I was hired by SMUD a number of steps were taken by the I&C department to correct these problems. Each and every part of the system was looked at and many changes and improvements were made that didn't show up until 1985.

I know that the wind instruments were physically moved on the tower to correct problems associated with the tower altering the wind. flow patterns. The shed housing the instruments was insulated and air i

conditioned. The shed was cleaned inside and I understand that prior to j

this that spiders had been getting into the electronic components. The i

cables were inspected and replaced, and the entire calibration procedures were reviewed and improved.

Additionally (as outlined in the report attached from Nov.

14, 1985) all other links in the system were questioned and problems were found and most have since been corrected.

During the past year the percentage of data collection has been vastly

improved - and at last report we were over 95%.

In addition to the improvements noted, we are in the process of installing an additional 10 Meter wind sensor to serve as a backup to the backup.

In the event of a total failure of the primary tower, dose calculations could be performed using the wind data from this secondary backup.

And, to take the backup one step further, we are in the process of obtaining a moden-based real-time weather data tap to Weather Services International. This will allow us to obtain complete weather information from all local weather observing stations in real-time, and for archive purposes.

The USI data also computes in real-time the Pasquill Stability Index values for all local stations.

Once this system is implemented we will be able to collect meteorological data for use in Emergency Planning from any SMUD site equipped with a modem and computer. We will thus be able to deal with a total failure of the Rancho Seco computer systen, or complete failure of the meteorological tower and/or backup wind tower.

As noted in the Lab Report section 4.2.2 there appear to be a number of inconsistencies in the frequency of stable lapse rates as nessured by Delta T. As noted earlier, many apparent surprises in Delta T can be explained by the unique meteorology of our micro-climate and the high frequency of summer inversions experienced in 1984, notwithstanding the instrument problems experienced that year.

With regard to spurious temperatures and deu point values noted, based on the Lab Report graphs and my own experience with the micro-climate, many of the inconsistencies noted are within climatological 1y explainable boundaries. However, several data points noted are clearly totally inconsistent with what is theoretically possible.

A problem that occurred in the 1984 data and is being corrected this year is the frequency of data entering the systen during times of calibration. It appears that some of the bad data values can be traced to times of calibration, and we have noted similar inconsistencies by using the Midas prograns to examine frequency of various data parameters.

Taking the system off-line during times of calibration and flagging bad data is a project underway at the present time.

Over the Winter' just past I noted some inconsistencies in the deu point readings. These problems were pointed out to Qualimetrics/ Weather Measure and steps have been taken to correct the readings.

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RECENT DATA QUALITY The attached 1985 report updates the state of the meteorological progran through the Fall. Additional progress has been made since that time.

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As noted earlier, steps are in progress to increase our backup data collection with the additional wind sensor and the WSI data tap.

We have also installed new matched temperature sensors from Rosemont Instruments. It is believed that these sensors represent the highest quality possible. Calibration of these sensors is now in progress.

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During the late Fall and early Winter, all cross correlation of temperature data were essentially perfect. This relationship held magnificently until a quarterly calibration was performed.

1 The delicate balance between the instruments changed and has held up to the present. No attempt has been made to ultra-fine tune the calibrations because of the expectation of the new Rosemont sensors.

i It must be noted with some sense of frustration, that the calibration

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procedures, as noted earlier in this report, which are designed to improve the readings of the instruments, have resulted in slight shifts in the readings, unfortunately throwing them out of perfect cross correlation.

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It should also be noted that cross correlation is not required by the NRC QA standards, but is something we are looking at internally in an i

attempt to achieve the highest level of data accuracy.

One encouraging note has emerged since last-fall, and that is the subtle shifts in cross correlation we have noted have been consistent -

that is, the relationships between sensors have remained essentially stable and predictable. These relationships have been the same whether the temperature has been in the 30's or in the 90's.-The degree of subtle difference has remained essentially constant throughout the entire range of both temperature and weather conditions.

l This gives me confidence that most, if not all, of the previous problems have been fixed, and we have now entered a condition where the I

gross-scale deficiencies have been for the most part been corrected, and we are attempting to fine-tune the system to an impeccable degree of accuracy.

It must also be noted, that none of this uculd or could have been possible without the combined efforts of everyone involved in the program, with each and every person working together in a concerted effort to improve the accuracy of the data.

One of the first problems I noticed when I began work on this situation last year was. that the various individuals involved in the-meteorological program were not connected and working as a group, not sharing information and communicating problems and solutions. This situation has been solved.

l CONCLUSIONS j

Since 1984 there has been considerable improvement in the Rancho Seco S'

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meteorological program. There has been a coordination of effort, each and every part of the system has been examined, and numerous problems have been discovered and fixed.

After the new sensors are calibrated the data will be monitored, and further decisions will be made if the data cannot be cross correlated to exacting standards.

Already anticipating potential problems, we are exploring ways to improve the calibration and monitoring procedures.

We are working on

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improving the computer monitoring of potential data errors. We are working on methods of insuring that bad data doesn't get into the system during times of calibration, and we are progressing toward a state of total preparedness for supplying meteorological data during any eventuality.

I am pleased that the constant monitoring of the data through the Winter, Spring, and Summer has shown a vastly improved stability in the readings over prior years.

I aa looking forward to continued progress in this regard.

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TON LOFFMAN CONSULTING METEOROLOGIST JULY 1, 1986 2

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