U-601452, Forwards Response to NRC Questions Raised at 890509 Meeting Re Environ Qualification Testing of Electrical Penetrations for Instrumentation at Plant.Encl 1 to Attachment a Withheld

Forwards Response to NRC Questions Raised at 890509 Meeting Re Environ Qualification Testing of Electrical Penetrations for Instrumentation at Plant.Encl 1 to Attachment a Withheld

ML20247B268
Person / Time
Site:	Clinton
Issue date:	05/17/1989
From:	Holtzscher D ILLINOIS POWER CO.
To:	NRC OFFICE OF INFORMATION RESOURCES MANAGEMENT (IRM)
Shared Package
ML19302D911	List: U-601452, Forwards Response to NRC Questions Raised at 890509 Meeting Re Environ Qualification Testing of Electrical Penetrations for Instrumentation at Plant.Encl 1 to Attachment a Withheld
References
U-601452, NUDOCS 8905240070
Download: ML20247B268 (6)

Text

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1U-601452 IA2- 89 ( 05- 17)-LP -

1A.120 ILLINCIS POWER COMPANY CLINTON POWER STATION, P.O. BOX 678, CLINTON, ILLINols 61727 1

May 17, 1989 Docket No. 50 '561 Document Control Desk Nuclear Regulatory Commission

.W ashington, D.C. .20555 Subj ect: Response to NRC Questions Concerning Environmental

't' Qualification Testing of Electrical Penetrations i for Instrumentation at Clinton Power Station

Dear Sir:

During the meeting between Illinois Power Company (IP) and NRC personnel on May 9, 1989 to discuss Clinton Power Station (CPS)

Environmental Qualification (EQ) issues, the NRC requested four items of information concerning the qualification testing for Cor.ax terminal l blocks associated with electrical penetrations for instrumentation at l CPS. Illinois Power agreed to provide this information prior to l entering Mode 2 (STARTUP) from the current (first) refueling' outage. l Attachment A to this letter provides IP's responses to the NRC's four l specific requests for information. ' Attachment B provides I.D's tasis for continued operation based on the qualification data for the terminal blocks and hardware improvements that will be made prior to entering

. Mode'2. j Enclosure 1 to Attachment A to this letter contains a document prepared by General Electric (CE) which is proprietary and was provided

, to IP under the terms of an agreement which forbids disclosure to others 3 except for disclosure to a governmental authority to the extent  ;

necessary to secure governr..,ntal authorizations. Accordingly/b

. requests that the-GE documant not be placed in the Public Document Room or otherwise publicly distributed.

We appreciated the opportunity to meet with the NRC to discuss these issues. Should you have any questions concerning the information q provided in this letter or its attachments, please call me.

Sincerely yours, .{

1 j

1~

%.4 ~ \

D. L. Holtzscher / h Acting Manager - f, j 517 Licensing and Safety M\

89052400 PDR ADO h h.OOO461PDC P

J WEB /krm Attachment (s) cc: NRC Clinton Licensing Project Manager NRC Resident Office NRC Region III, Regional Administrator Illinois Department of Nuclear Safety l

l

f Attachmsnt A x

s .t Responses to NRC Requests for Information on Electrical Penetrations for Instrumentation u

-1. NRC Request - " Provide documentation on the acceptable amount of leakare current for the affected instruments".

IP Response - General Electric (GE) and Sargent and Lundy (S&L) have performed worst case analyses to-determine the effect of the leakage current levels observed during qualification testing of n the terminal blocks on instrumentation served by the terminal blocks. These analyses were based upon leakage current levels identified in Conax Test Report IPS-650. In summary, the results N' of these analyses show that leakage consistent with the data obtained during the qualification tests would have a negligible effect on instrument accuracy or operator evaluation of instrument readings. Further, these amounts of leakage current.were determined to have no safety consequences. Copies of the GE and S&L analyses are appended as Enclosure 1 to this Attachment.

2. NRC Request " Provide a qualitative or quantitative analysis that compares-the containment enviroggent under accident conditions to the test chamber environment and how the differences may a ffect test results".

IP Response - The containment conditions to Which the Conax

, terminal blocks associated with the electrical penetrations for instrumentation could be subjected have been compared with the conditions under Which environmental qualification testing for these items was performed. The results of this comparison demonstrate that the conditions under Which the terminal blocks were tested bound the postulated temperature, pressure and

~

j humidity conditions for the terminal blocks at CPS. In particular, the Conax Test Report IPS-650 shows the test chamber environment to have been a saturated steam environment, Which bounds the worst-case humidity condition in the containment (actuation of containment spray). As described below in response to NRC Request No. 3, the data and conditf-ns observed during testing, and a replication of the test conditions on May 8, 1989, showed several indications that a saturated steam environment was present during qualification testing of the terminal blocks.

Similarly, the test conditions included temperatures (261 - 264*F) and pressures (20.3 psig) that bound the worst postulated levels at CPS (185'F and 15 psig, respectively). The qualification testing did not include spray conditions; however, prior to entering Mode 2 (STARTUP), IP will make hardware changes that will l preclude spray from impinging on the terminations associated with instrument penetrations (see IP's response to NRC Request No. 4, below). Furthermore, GE has estimated the containment relative humidity levels (absent containment spray actuation) that would be present during the first 2.4 hours4.62963e-5 days <br />0.00111 hours <br />6.613757e-6 weeks <br />1.522e-6 months <br /> following the occurrence of a recirculation line break. These humidity levels are assumed to start at 100% for analysis purposes, but remain at or below 77%

(A-1)

Attechment A t

for the remainder of this period. The Conax test conditions $

included relative humidity levels of 100% (see the response to NRC 0 Request No. 3 below). Thus, the test data bounds the actual estimated humidity conditions.

3. NRC Request - " Provide documentation of the moisture deposition tests run on 5/8/89 at Conax and their anolicability to the auslification test run on the electrical penetration".

IP Response - The data from the original Conax qualification tests for the terminal blocks (described in Conax Test Report IPS-650) and conditions observed by Conax personnel during those tests indicate that saturated steam and moisture deposition conditions were present. First, during the test, steam was provided to the test chamber from the boiler without the use of superheaters.

This arrangement was designed to provide srturated steam to the test chamber. Second, qualification test data indicate that saturated conditions existed in the test chamber. Due to the accuracy and location of instruments installed inside the test chamber, there is a band of temperatures and pressures (approximately 4* Fahrenheit and 2 psi) within which saturated steam conditions can be assumed to be present. See Letter from Wyle Laboratories to S&L dated May 5, 1989 (this letter was provided to the NRC on May 9, 1989). The temperatures and pressures recorded during the Conax qualification test have been plotted by IP and, for almost all measurements, were within this band of temperatures and pressures. Finally, Conax personnel observed water in the test chamber during and immediately after the test. Each of these factors demonstrates the existence of saturated steam in the test chamber.during the original qualification tests.

, Tests were performed at Conax on May 8, 1989 that replicated the pressure and temperature conditions that were utilized in the original qualification tests of the terminal blocks. The purpose of the May 8, 1989 test was to confirm that the original test conditions included saturated steam conditions and moisture deposition. During the May 8, 1989 testing, several indications of such conditions were present, including: a) water accumulated in beakers placed in the test chamber, b) absorbant powder placed in the test chamber became gummy from moisture, and c) a paper towel placed in the test chamber absorbed water and dripped when

, removed. These tests therefore confirm that the original testing l included saturated steam and moisture deposition conditions. A report describing the results of the May 8, 1989 test in more detail is appended as Enclosure 2 to this Attachment.

4. NRC Request - "What is IP's course of action to resolve NRC concerns on the qualification testine involvine terminal blocks?

Provide your program scope and_ Schedule",

t-IP Response - As'noted above and in Attachment B, there is reasonable assurance that the terminal blocks will be able to perform their safety function under postulated accident 2

(A-2)

L L_ _ _ . _ _ _ _ _ _ ._. _ _. _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _

Attachment A conditions. The conditions during the qualification tests included saturated steam and bound the postulated conditions in the CPS containment as a result of a design basis accident.

Additionally, the amount of leakage current observed during the qualification tests would have a negligible effect on instrument accuracy or operator evaluation of instrument readings, and would have no safety consequences. Therefore, the terminal blocks are qualified for the postulated conditions at CPS.

In order to resolve issues relating to spray, and to provide further assurance that terminations associated with electrical penetrations for instrumentation are capable of functioning during harsh environment conditions, IP will take the following actions prior to entering Mode 2 (STARTUP) from the current (first) refueling outage.

a. With respect to the top-entry penetration for Division III instrumentation, IP will replace the terminal strip terminations with Raychem-insulated splices.

This action will obviate the need for caulking or sealing the penetration.

b. With respect to the top-entry penetration for Division I instrumentation, IP will seal the cable entry with a protective boot and will caulk the penetration j enclosure to prevent spray from impinging on tho.

terminal strips.

c. With respect to the remaining penetrations for instrumentation (which are bottom-entry penetrations),

IP will caulk the penetration enclosures to prevent spray from impinging on the terminal strips.

Prior to the end of the next (second) refueling outage, IP will replace the remaining terminations associated with penetrations for instrument cables with splices insulated with Raychem or other qualified devices.

4 (A-3) i

b Enclosure 1 to Attachment A P

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