SNRC-1578, Provides Info Re Temp Profile Inside Primary Containment Used for Environ Qualification.Results of Review of Actual Test Temps Indicate Sufficient Margin Exists to Envelope Supporting Calcuation & Environ Qualification Profile

Provides Info Re Temp Profile Inside Primary Containment Used for Environ Qualification.Results of Review of Actual Test Temps Indicate Sufficient Margin Exists to Envelope Supporting Calcuation & Environ Qualification Profile

ML20248E052
Person / Time
Site:	Shoreham File:Long Island Lighting Company icon.png
Issue date:	04/04/1989
From:	Leonard J LONG ISLAND LIGHTING CO.
To:	NRC OFFICE OF INFORMATION RESOURCES MANAGEMENT (IRM)
References
SNRC-1578, NUDOCS 8904120115
Download: ML20248E052 (3)

Text

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S O M NU POWE ST T

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• WADING RIVER. N.Y.11792 JOHN D. LEON ARD, JR.

wconesiorm.mucuan onnmous SNRC-1578 APR 4 269 U. S. Nuclear Regulatory Commission Attn: Document Control Desk Washington, DC 20555 Temperature Profile Inside Primary Containment Used For Environmental Qualification Shoreham Nuclear Power Station - Unit 1 Docket No. 50-322 i

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Gentlemen:  ;

During the recent operational readiness assessment team {

inspection, LILCO provided NRC inspectors with a copy of the  !

engineering calculation that was used to establish the enveloping temperature conditions used for environmental qualification of j equipment in the primary containment. As a result of their review, the inspectors raised two questions which were addressed by LILCO during the inspection and were discussed at the March 23, 1989 exit meeting. This letter provides information that answers the questions and should enable NRC Staff environmental qualification specialists to consider the issue closed.

Primary Containment Temperature Exceeds the EQ Temperature Limits For A Short Period of Time A series of calculations have been performed to define the enveloping conditions to be used for environmental qualification of the equipment in the primary containment. Such analyses have been performed with multiple failures, no operator action, and in some cases additional margin of safety in order to assure that environmental qualification of the equipment would envelope the design basis accidents of Shoreham Nuclear Power Station. This multilevel of conservatism was desirable because the development of the EQ pressure and temperature envelopes was concurrent with some design changer being made to the primary containment (Mark II program) in the 1981-3 timeframe. These design modifications had significant impact on the pressure and temperature responne of the primary containment to a LOCA.

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G904120115 DR e904o4 p ADOCN 05000322 PDC

SNRC-1578 l Page 2 of 3 l Page B2 of calculation US(B)-185 shows the primary containment l temperature response to a loss-of-coolant accident with one train of RHR (one pump per train) and one core spray system being available for mitigation of a loss-of-coolant accident. The transient, called case D in the SNPS USAR, does not take any credit for operator action to actuate the primary containment spray system. A comparison of this temperature response with the EQ temperature limits (attached figure) shows that the primary containment temperature would exceed the EQ temperature temperature limits for a relatively short period of time.

SWEC calculation ll600.02-EQ-39 has been performed to demonstrate '

that the EQ temperature profile used for qualification of the equipment in the primary containment (Figure D-1 of the EQ report) would have sufficient conservatism to bound the temperature response to LOCA case D as described in the USAR and calculation US(B)-185 and 169-2. This calculation, which was provided to an NRC inspector, shows that using the Arrhenius Methodology described in Section 3.4.5 of the Shoreham Environmental Qualification Report, the EQ temperature envelopes exceed the composite temperature profile of MSLB and LOCA case D of the SNPS-USAR with a margin of safety in excess of 25 percent.

Notwithstanding the above referenced calculation, LILCO performed a review of EQ equipment in the drywell. A review of the actual test temperature profiles of the affected equipment was performed. The results indicate that sufficient margin exists in the tested temperature profile to envelope the supporting calculation and EQR profile in the time interval in question.

LILCO intends to finalize the results of this review in a documented report.

30*F Addition SWEC calculation 11600.02-US(b)-185 was performed to produce the above mentioned conservative upperbounds for the EQ envelopes.

At the time of the original calculation, 30 F was suggested to be added to temperature limits due to unavailability of the building response to a main steam line break. Such added margin was later determined to be unnecessary due to the significant level of conservatism already existing in the design basis of the plant.

Follow-up calculations such as ll600.02-US(b)-169-02 and 1160.02-ES-59-1 demonstrated that such margin was not needed.

The design basis analyses documented in these two calcr ations, LOCA and MSLB respectively, were shown to be well wit .a the EQ temperature limits defined previously and without the 30 F margin.

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SNRC-1578 Page 3.of 3.'

Should you have any. questions on the information'provided above,- '

. please do not hesitate to call my office.

Very truly yours,-

,).

Gyjm.

• -John D. L ard, Jr.

Vice President'- Nuclear Operations ,

GJG/ds cc: S. Brown.

W.' Russell

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