ML20155F560

Informs That Based on Review,Pool Dynamic Loads Specified for Plant Found to Be Acceptable Provided Util Adopts Listed Positions

ML20155F560
Person / Time
Site:	Grand Gulf, 05000000
Issue date:	10/22/1975
From:	Tedesco R Office of Nuclear Reactor Regulation
To:	Deyoung R Office of Nuclear Reactor Regulation
Shared Package
ML20155E140	List: ML20155E133 ML20155E182 ML20155E227 ML20155E338 ML20155E354 ML20155E367 ML20155E405 ML20155E430 ML20155E447 ML20155E473 ML20155E503 ML20155E550 ML20155E557 ML20155E565 ML20155E578 ML20155E600 ML20155E714 ML20155E728 ML20155E753 ML20155E770 ML20155E794 ML20155E948 ML20155E967 ML20155E986 ML20155F001 ML20155F053 ML20155F176 ML20155F191 ML20155F203 ML20155F217 ML20155F228 ML20155F252 ML20155F279 ML20155F302 ML20155F332 ML20155F378 ML20155F477 ML20155F485 ML20155F516 ML20155F534 ML20155F545 ML20155F560 ML20155F589 ML20155G308
References
FOIA-88-91 NUDOCS 8806160429
Download: ML20155F560 (4)

Text

UNITED ST AVES NUCLEAR REGULATORY COMMissl0N g?) W ASHINGTON, D. C. 20555 i

OCT 221975 R. C. DeYoung, Assistant Director for Light Water Reactors, Group 1, RL GRAND GULF 1 AND 2 - EVALVATION OF POOL DYNAMIC LOADS (TAR-1579)

Plant Name: Grand Gulf I and 2 Docket Hos.: 50-416/417 Licensing Stage: Post CP Project Manager: E. Butcher Requested Completion Date: October 15, 1975 Technical Review By: Containment Systems Branch Description of Task: Evaluate 8/15/75 Submittal by MPSL Review Status: Complete As part of our continuing evaluation of pool dynamic loads for Grand Gulf (TAR-1579), the Containment Systems Branch has reviewed the applicant's submittal of August 15, 1975. This document provides l clarification of the Grand Gulf design to acconcodate pool dynamic l Icads as requested in the HRC's letter to MP&L (W. Butler to H.

Stanpley) dated June 23, 1975. Based on our review, we would find i the pool dynamic loads specified for Grand Gulf to be acceptable provided the applicant adopts the following positions:

1. Struct~ ural protuberances from the drywell; specifically, the drywell equipment hatch, the .drywell personnel lock, and the containment personnel lock should be extended into the suppression pool and designed for coincident loads due to air bubble (equal to peak drywell prersure) and pool drag (based on a pool swell surface velocity of 40 ft/sec). l

2. Confinn that the asymmetric bubble load on the containment, discussed on Page 72 of the August 15, 1975, l'P&L letter, is a design basis load.

3. Confirm that the loads due to actuation of safety relief valves with a ramshead discharge, and which are used as a design basis for the Grand Gulf design, have been cal-culated using the analytical model described in NEDE-20942P.

4. Safety rel',ef valve loads on structures submerged in the suppression pool should be based on a ramshead discharge.

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5. The oscillatory safety relief valve bubble load should be i applied to the design of all' submerged structures in the suppression pool. .

6. Confirm that the load due to actuation of two adjacent safety relief valves is considered to be a design basis event for the Grand Gulf plant consistent with the speci- i fications of NEDE-ll314-08. ,

. i The above positions are consistent with the standard acceptance criteria developed for MARK III pool dynamic loads and currently being applied ,

to all plants with' MARK III containments.

' T r

Qp(1rc.'2Nc-Robert L. Tedesco, Assistant Director for Containment Safety ,

Division of Technical Review  ;

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F. e.. seder R. Boyd w/o enc 1.

W. Mcdonald w/o encl.

W. Butler E. Butcher -

R. Maccary '

G. Lainas

J. Kudrick -

4 J. ShapaKer J. Glynn E.Jacobs R. Cudlin l I i J

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, 10/17/75 r l R. C. DeYoung, Assistant Director for Light Water Reactors, Group 1. RL GRAND GULF 1 AND 2 - EVALUATION OF P0OL DYNAMIC LOADS (C0HH40ATivs UF ---

TAR -1579)

Plant Name: Grand Gulf 1 and 2 Docket No's: 50-416/417 Licensing Stage: Post CP .

i Project flanager: E. Butcher Requested Completion Date: October 15, 1975 Technical Review By: Containment Systems Branch Description of Task: Evaluate 8/15/75 Submittal by i1P&L ,

Review Status: Complete  ;

As part of our continuing evaluation of pool dynamic loads for Grand Gulf (TAR-1579),the Containment Systems Branch has reviewed .the applicant's submittal of August 15,15 5. This document provides clarification of the Grand Gulf design to accommodate pool dynamic loads as requested in the NRC's letter to MP&L (W. Butler to N. Stampley) dated June 23, 1975.

Based on our review, we would find the pool dynamic loads specified for j Grand Gulf to be acceptable provided the applicant adopts the following posi tions:

1. Structural protuberances from the drywell; specifically, the drpell equipment hatch, the drywell personnel lock, and the  ;

containment personnel lock should be extended into the sup-pression pon1 and designed for coincident loads due to air bubble f (equal to peak drywell pressure) and pool drag (based on a pool swell surface velocity of 40 ft/sec).

I

2. Confim that the asymetricbubble load on the containment, dis-  ;

cussed on Page 72 of the August 15, 1975, fiP&L let'ter, is a i design basis load. l

3. Confim that the loads due to actuation of safety relief valves l l

i l

t I 's with a ramshead discharge, and which are used as a design 1

basis for the Grand Gulf design, have been calculated using j the analytical model described in NEDE-20942P.

4. Safety relief valve loads on structures submerged in the suppression pool should be based on a ramshead discharge.

5. The oscillatory safety relief valve bubble load should be applied to the design of all submerged structures in the suppression pool.

6. Confirm that the load due to actuation of two adjacent safety relief valves is considered to be a design basis -

event for the Grand Gulf plant consistent with the speci-fications of NEDE-ll314-08.

The above positions are consistent with the standard acceptance criteria developed for MARK III pool dynamic loads and currently being applied to all plants with MARK III containhents. I Robert L. Tedesco, Assistant Director for Containment Safety Division of Technical Review Concurrences:

RCudlin JKudrick Glainas ,

RTedesco l Distribution:

Docket File l NRR Reading File CS Reading File CSB Reading File

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