ML20100K740

Forwards Response to 850403 Questions Re Environ Qualification of Foxboro Pressure transmitters.Post-accident Monitoring Pressure Transmitters Replaced W/Barton Model 764

ML20100K740
Person / Time
Site:	Sequoyah
Issue date:	04/08/1985
From:	Domer J TENNESSEE VALLEY AUTHORITY
To:	Harold Denton Office of Nuclear Reactor Regulation
References
NUDOCS 8504160061
Download: ML20100K740 (4)

Text

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e TENNESSEE VALLEY AUTHORITY CHATTANOOGA. TENNESSEE 374ol 1630 Chestnut Street Tower II April 8, 1985 Mr. Harold R. Denton, Director Office of Nuclear Reactor Regulation U.S. Nuclear Regulatory Commission Washington, D.C. 20555

Dear Mr. Denton:

In the Matter of ) Docket Nos. 50-327 Tennessee Valley Authority ) 50-328 On April 3,1985 ya. staff submitted informally several questions regarding environmental qualification of Foxboro pressure transmitters. TVA has reviewed those questions and have prepared responses which are contained in the enclosure.

If you have any questions, please call R. E. Alaup at FTS 858-2725.

Very truly yours, TENNESSEE VALLEY AUTHORITY e' . J. A. Domer Nuclear Engineer Sworn to and subscribed before me this -P day of 60_l/ 1985 Y l $d b Notary Public t

My Commission Expires 6</W/M Enclosure oc (Enclosure):

U.S. Nuclear Regulatory Commission Region II Attn: Dr. J. Nelson Grace, Regional Administrator 101 Marietta Street, NW, Suite 2900 Atlanta, Georgia 30323 Mr. Carl Stahle U.S. Nuclear Regulatory Commission Sequoyah Project Manager 7920 Norfolk Avenue Bethesda, Maryland 20814 k I l 8504160061 850408 8 PDR ADOCK 05000327 P PDR An Equal Opportunity Employer .

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ENCLOSURE ENVIRONMENTAL QUALIFICATION OF FOXBORO PRESSURE TRANSMITTER MODEL E11GM (NON-MCA) FOR SEQUOYAH NUCLEAR PLANT Introduction '

The Office of Engineering (OE) has the responsibility for determination of environmental qualification of components and preparation of NCRs and FE/ERs. This information is transmitted by the Office of Engineering-Nuclear Engineering Branch's Chief Nuclear Engineer to the plant Site Director. Site personnel in Nuclear Power, as the owner operator, has the responsibility for preparing a safety evaluation,, determining equipment operability and reportability. With this in mind, the i following responses to the NRC questions provides TVA's position and basis regarding pressure transmitters 1 and 2, PDT-30-42, -43, -44, and

-45.

NRC QUESTION

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a. Were the subject transmitters environmentally qualified at the time Revision 0 of the NCR and the associated FE/ER were approved by the Chier Nuclear Engineer? If it was considered qualified provide the basis for that determination.

TVA RESPONSE The subject transmitters were qualified for interim use in accordance with 10 CFR 50.49 when Revision 0 of the NCR and associated Failure Evaluation / Engineering Report (FE/ER) were approved by the Chief Nuclear Engineer, Nuclear Engineering Branch.

The subject transmitters were initially evaluated in Sept 0mber 1981 and May 1982. Based on their similarity with other qualified transmitters, the subject transmitters were deemed qualified for eight years. When RO of the NCR was prepared, a concern was documented regarding postaccident accuracy requirements versus transmitters accuracy. RO of the FE/ER assumed that the test data of a similar tested transmitter could not support the accuracy requirements of the Final Safety Analysis Report (FSAR) as documented by RO of the NCR. These evaluations were actually based on a misinterpretation of test data in that the similar transmitters were tested in a more severe environment than the SQN specific environment where all the transmitters are physically located.

Therefore, based upon the above, a reevaluation was performed.

NRC QUESTION

b. Were the subject transmitters operable at the time Revision 0 of the NCR and FE/ER were approved by the Chier Nuclear Engineer? If it was considered operable, provide the basis for that determination.

TVA RESPONSE The subject transmitters were OPERABLE and were never declared inoperable. The transmitters PDT-30-44 and -45 are postaccident

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s monitoring (PAM) instruments (LCO 3 3 3 7). These two instruments had been demonstrated operable by performance of a channel check and channel _

calibration as required by surveillance requirements. The PAM transmitters were not declared inoperable due to Revision 0 of this NCR and FE/ER since the approach taken was in error. Specifically, the transmitters were located outside primary containment and the accuracy applied in the FE/ER was that associated with similar transmitters I

located inside containment. It was determined upon initial receipt that

the approach taken in the FE/ER was based on a misinterpretation of test data and it was determined before the expiration of the NCR procedure time limits that the accuracy requirement of the FSAR.could be met. The other.two transmitters (PDT-30-42 and -43) are non-PAM indicators and were incorrectly included within the scope of the NCR and FE/ER. All four of these transmitters perform their short-term safety-functions (high one, high two containment pressure) before the environment becomes harsh and are considered operable as required by LOO 3 3.2.1.

NRC QUESTION J

c. - Were the subject transmitters environmentally qualified at the time

, Revision 1 of the NCR and FE/ER were approved by the Chief Nuclear Engineer? If it was considered qualified, provide the basis for

• that determination.

1 TVA RESPONSE

, The subject transmitters were qualified for interim use in accordance t

- with 10 CFR 50.49 when Revision 1 (R1) of the NCR and associated FE/ER-

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- were approved by the Chief Nuclear Engineer, Nuclear Engineering Branch. .

Revision 1 of the NCR was issued to remove PDT-30-42 and -43 These transmitters are not required for long -term postaccident monitoring and, therefore, were still considered qualified per the original 1981/1982 evaluation. R1 of the failure evaluation was written to incorporate the '

correct interpretation of the test data of the similar transmitters and to remove PDT-30-42 and -43 The evaluation contained in the equipment qualification sheet and l_ - justification for continued operation concluded that the subject transmitters, PDT-30-44 and -45, were qualified for interim use in A

accordance with 10 CFR 50.49.

NRC QUESTION i

d. Were the subject transmitters operable at the time Revision 1 of the NCR and FE/ER were approved by the Chier Nuclear Engineer? If it

was considered operable, provide the basis for that determination.

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-e TVA RESPONSE The non-PAM transmitters (PDT-30-42, -43) were not within the scope of Revision 1 to the NCR and FE/ER. The PAM transmitters were OPERABLE in accordance with LCO 3.3 3 7. Their operability was based on channel checks, and channel calibrations performed in accordance with applicable surveillance requirements. In addition, the accuracy of the subject transmitters was shown in the FE/ER to be within that allowed by the FSAR.

NRC QUESTION

e. Provide the current status of these transmitters with respect to environmental qualification and operability, and the bases for these determinations.

TVA RESPONSE The PAM pressure transmitters (PDT-30-44 and -45) have been replaced with transmitters (Barton Model No. 764) which are environmentally qualified, independent of similarity. Environmental qualification for this instrument is documented in Westinghouse letter from Ed Novotnak to J. A. Raulston dated January 22, 1985 (WAT-D-6354) and Westinghouse test report WCAP-8687, Supplement 2, E03A, Revision 2. In addition to the transmitter accuracy given in the Westinghouse letter above, the total  !

loop accuracy has been calculated as a maximum of 4.6 percent. This is a much tighter accuracy than is currently stated in SQN's FSAR (10 percent) for maintaining containment integrity. Thus, PDT-30-44 and -45 are environmentally qualified independent of similarity and operable.

PDT-30-42 and -43 are non-MCA Foxboro E11GMs. These transmitters are nor.-PAM indicators and were inaccurately included within the scope of the NCR and FE/ER. These transmitters, in combination with PDT-30-44 and

-45, will perform their short-term safety functions (high one, high two containment pressure) before the environment becomes harsh and are operable as required by LCO 3.3 2.1.

It should be pointed out that the PAM pressure transmitters were replaced to eliminate any question as to the environmental qualifications of the transmitters and at no time were the transmitters considered inor:rable.

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