05000423/LER-1996-045-01, :on 961107,electrical Separation Design Conflict with FSAR Identified.Caused by Breakdown in FSAR Revision Process.Design Basis Will Be Revised to Identify Deviations from Reg Guide 1.75,Position C.6

:on 961107,electrical Separation Design Conflict with FSAR Identified.Caused by Breakdown in FSAR Revision Process.Design Basis Will Be Revised to Identify Deviations from Reg Guide 1.75,Position C.6

ML20135E856
Person / Time
Site:	Millstone
Issue date:	12/06/1996
From:	Brothers M, Perschel J NORTHEAST NUCLEAR ENERGY CO., NORTHEAST UTILITIES
To:	NRC OFFICE OF INFORMATION RESOURCES MANAGEMENT (IRM)
Shared Package
ML20135E843	List: 05000423/LER-1996-045, Forwards LER 96-045-00,documenting Condition That Was Determined at Millstone Unit 3 on 961107.LER Submitted Pursuant to 10CFR 50.73(a)(2)(ii).Commitments Encl 05000423/LER-1996-045-01, :on 961107,electrical Separation Design Conflict with FSAR Identified.Caused by Breakdown in FSAR Revision Process.Design Basis Will Be Revised to Identify Deviations from Reg Guide 1.75,Position C.6
References
RTR-REGGD-01.075, RTR-REGGD-1.075 LER-96-045-01, LER-96-45-1, NUDOCS 9612120120
Download: ML20135E856 (4)

LER-1996-045, on 961107,electrical Separation Design Conflict with FSAR Identified.Caused by Breakdown in FSAR Revision Process.Design Basis Will Be Revised to Identify Deviations from Reg Guide 1.75,Position C.6

Event date:
Report date:
4231996045R01 - NRC Website

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N'iC FORM 366 U.S. NUCLEAR REGULATORY COMMISSION APPROVED BY OMS NO. 3150-0104

(#-95)

EXPIRES 04/30/98

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!?!?!Nh*'#o%!E^o"."n"I n%'#T"o."&i'an"' *-

u (See reverse fOr required number of digits / Characters fOr each block)

Fi.CIUTY NAME (1)

DOCKET NUMBER (2)

PAGE (3)

Millstone Nuclear Power Station Unit 3 05000423 1 of 4 i

TITLE I4)

Electrical Separation Design Conflict with FSAR EVENT DATE (5)

LER NUMBER (6)

REPORT DATE (7)

OTHER FACILITIES INVOLVED (8)

MONTH DAY YEAR YEAR SEQUENTIAL REVISION MONTH DAY YEAR FAcluTY NAME DOCKET NUMBER NUMBER 11 07 96 96 045 00 12 06 96 OPERATING THis REPORT IS SUBMITTED PURSUANT TO THE REQUIREMENTS OF 10 CFR 5: (Check one or more) (11)

MODE (M 5

20.22o1(b) 20.2203(a)(2)(v)

So.73(a)(2)(i)

So.73(a)(2)(viii)

POWER 20.22o3(a)(1) 20.2203(a)(3)(i)

X so.73(a)(2)(ii)

So.73(a)(2>(x)

LEVEL (10) 000 20.2203(a)(2)(i) 20.2203(a)(3)(ii) so.73(a)(2)(iii) 73.71

+

on in..% u s

20.2203(a)(2)(ii) 20.2203(a)(4)

So.73(a)(2)(iv)

OTHER a

Ph * 'l or in NRC Form 366A HMW 4

4 LICENSEE CONTACT FOR THis LER (12)

NAME TELEPHONE NUMBER unclude Area Codel J.M. Peschel, MP3 Nuclear Licensing Manager (860)437-5840 2

COMPLETE ONE LINE FOR EACH COMPONENT FAILURE DESCRIBED IN THIS REPORT (13)

CAUSE

SYSTEM COMPONENT MANUFACTURER REPORTABLE

CAUSE

SYSTENI COMPONENT MANUFACTURER REPORTABLE TO NPRD3 TO NPROS

,4 o

SUPPLEMENTAL REPORT EXPECTED (14)

EXPECTED MONTH DAY YEAR SUBMISSION f NO YEs (If yes, complete EXPECTED SUBMISSION DATE).

ABSTRACT (Limit to 1400 spaces, i.e., approximately 15 single-spaced typewritten lines) (16)

On October 23,1996, with the plant in Mode 5, several cases of electrical separation deviations dispositioned and approved by engineering during construction and early operation, were identified as potentially not meeting the clectrical separation criteria specified in the Final Safety Analysis Report (FSAR). On November 7,1996, subsequent engineering evaluation confirmed that these conditions did nvi meet the FSAR separation criteria. As a l

result an immediate notification was made on November 7,1996, pursuant to 10CFR50.72(b)(1)(ii)(B) as a condition outside the design basis of the plant.

There were no adverse safety consequences from this condition, in that tne Linit has not experienced an event as a result of a failure in electrical separation nor has it experienced an event which was aggravated by a failure in clectrical separation of circuits or equipment. However, the conditions identified are significant because they represent conditions outside the design basis of the plant.

i The plant will be modified to conform to the existing design basis, or the design basis will be revised to identify deviations from Regulatory Guide 1.75, Position C.6.

9612120120 961206 PDR ADOCK 05000423 S

PDR

NRC SchM 366A U.S. NUCLEAR REGULATORY Commission i4 95)

LICENSEE EVENT REPORT (LER)

TEXT CONTINUATION FACILITY NAME (1)

DOCKET NUMBER (2)

LER NUMBER (6)

PAGE (3)

YEAR SEQUENTIAL REvlsioN Millstone Nuclear Power Station Unit 3 05000423 NUMBER NUMBER 2 of 4 96 045 00 TEXT (If more space is required, use additional copies of NRC Form 366A) (11) 1.

DescriDtion of Event On October 23,1996, with the plant in Mode 5, several cases of electrical separation deviations dispositioned and approved by engineering during construction and early operation, were identified as potentially not meeting the el:ctrical separation criteria specified in the Final Safety Analysis Report (FSAR), On November 7,1996, subsequent l

cngineering evaluation confirmed that these conditions did not meet the FSAR separation criteria. As a result an immediate notification was made on November 7,1996, pursuant to 10CFR50.72(b)(1)(ii)(B) as a condition outside the j

d: sign basis of the plant.

11.

Cause of Event

The cause of this noncompliance with electrical separation requirements was a breakdown in the FSAR revision process. It was the understanding at the completion of construction, that on a case-by-case basis, deviations i

from general installation criteria did not have to be reflected in the FSAR.

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111. Analysis of Event l

During an investigation into electrical separation issues, deviations taken against Stone & Webster (S & W)

Specification E350, " Electrical Installation," during plant construction and early operation were identified that were in conflict with the separation criteria specified in the FSAR. Each deviation was documented on Engineering and J

D: sign Coordination Reports (E&DCRs) or Nonconformance and Disposition Reports (N&Ds), dispositioned, and i

approved for hstallation in accordance with S & W procedures. Tectnical justification was included within the documentation for accepting each of these one-time deviations :ind the engineering design documents acknowledged that the conditions were exceptions to the FSAR electrical separation criteria.

El:ctrical separation requirements were established within the electrical installation specification based upon the guidance of IEEE Standard 384-1974, " Draft American National Standard, IEEE Trial-Use Standard Criteria for S:paration of Class 1E Equipment and Circuits." NRC Regulatory Guide (RG) 1.75, "PhysicalIndependence of El ctrical Systems," augments the standard and defines the NRCs* positions on electrical separation. The j

regulatory guide provides descriptions of sanctioned variances, and provides the requirements to deviate from the i

standard. FSAR Table 1.8-1 states the degree of compliance to RG 1.75 and lists exceptions or clarifications.

RG 1.75, Section C.6 states in part: " Analyses performed in accordance with Sections 4.5(3),4.6.2, and 5.1.1.2 [of IEEE Standard 384], should be submitted as part of the Safety Analysis Report and should identify those circuits installed in accordance with these sections." Testing was performed at the Wyle Test Laboratory to test the design adequacy of various worst case configurations of electrical raceways. This testing and analysis, allowed by IEEE Specification 384 and endorsed by RG 1.75, provides the basis for reduced spatial separation from the generic IEEE specification separation requirements.

Position C.6 of RG 1.75 is clarified within FSAR Table 1.8-1, and states in part: " Analysis of minimum separation distance in Section 5.1.1.2 of IEEE 384 is accomplished by the following: Test and analysis performed to d,termine the separation requirements between Class 1E and non-Class 1E is presented in Wyle Test Report No.

47506-02." The NRC issued Supplement 3 to the SER finding field installations that were in accordance with the Wyle tested configurations acceptable. However, Supplement 3 specifically states, "These separations are applicable only between Class 1E and non-Class 1E circuits."

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NRQ FORM 366A U.S. NUCLEAR REGULATORY Commission (4-95)

LICENSEE EVENT REPORT (LER)

TEXT CONTINUATION FACILITY NAME (1)

DOCKET NUMBER (2)

LER NUMBER (6)

PAGE (3)

YEAR SEQUENTIAL REVislON Millstone Nuclear Power Station Unit 3 05000423 NUMBER NUMBER 3 of 4 96 045 00 TEXT (11more space is required, use additional copies of NRC Form 366A) (17)

The test report conclusions, while technically justified, were improperty applied. First, while the conclusions of the Wyle Labs test report, for the tested configurations, are considered valid for non-Class 1E fo Class 1E, and Class 1E to Class 1E configurations, the NRC has not approved usage of the report at Millstone Unit 3, for Class 1E to Class 1E applications. However, the test report was used to justify several minimum electrical separation d:viations involving Class 1E circuits. Second, during the dispositioning of electrical separation deviations, the j

findings of the test report were utilized to justify not having to rework deviations that corresponded to a configuration not explicitly included in the SER, but considered to be effectively the same as a tested configuration.

Usage of the test report for Class 1E to Class 1E separation applications was outside the bounds of its applicability 1

approved by the NRC within the SER. Using the test report to justify minimum separation deviations for a configuration not explicitly included in the SER is incorrect. The equivalence of the two configurations had not been established from a licensing perspective. FSAR Table 1.8-1 and Section 8.3.1.4.2 were not updated to reflect this application of reduced separation criteria as allowed by the regulatory guide, the type of installation d:viations, and describe the justification for the deviations.

There were no adverse safety consequences from this condition, in that the unit has not experienced an event as a r:sult of a failure in electrical separation nor has it experienced an event which was aggravated by a failure in circtrical separation of circuits or equipment. However, the conditions identified are significant because they represent conditions outside the design basis of the plant.

IV. Corrective Action

No immediate actions were required on November 7,1996 as the plant was in a shutdown condition at the time of discovery and remained shutdown for unrelated reasons.

The following corrective action will be taken:

1. The plant will be modified to conform to the existing design basis, or the design basis wi;l be revised to identify deviations from Regulatory Guide 1.75, Position C.6, prior to restart.

V.

Additional Information

j I

None

~ Similar Events LER 96-015-02 *lnadeauste Electrical Seoaration Between Redundant Pretection Trains Associated withReactor Trio Switches and Reactor Trio Breaker Indicatina Liahts."

This LER involved a noncompliance with electrical separation requirements between the manual reactor tripswitch and the breaker indicating lights for redundant reactor protection trains.

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iU.S. NUCLEAR REGULATORY COMMISSION LICENSEE EVENT REPORT (LER)

TEXT CONTINUATION FACILITY NAME (1)

DOCKET NUMBER (2)

LER NUMBER (6)

PAGE (3)

YEAR SEQUENTIAL REVISION Millstone Nuclear Power Station Unit 3 05000423 NUMBER NUMBER 4 Of 4 96 045 00 TEXT (11more space is required, use additional copies of NRC Form 366A) (17)

Manufacturer Data Ells Systern Code A_rchitect Enoineer l

Not Applicable Stone & Webster Engineering Corporation l

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OC FORM 366A (&95)