ML20030A797
| ML20030A797 | |
| Person / Time | |
|---|---|
| Site: | Midland |
| Issue date: | 07/23/1981 |
| From: | Jackie Cook CONSUMERS ENERGY CO. (FORMERLY CONSUMERS POWER CO.) |
| To: | Harold Denton Office of Nuclear Reactor Regulation |
| References | |
| 13364, NUDOCS 8107290047 | |
| Download: ML20030A797 (3) | |
Text
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4 CODSumBIS Power James W Cook Vice President - Projects, Engineering and Construction General officos: 1945 West Pernell Road, Jackson, MI 49201 * (517) 788 0453 July 23, 1981 D
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2 N L a s1981
>l Harold R Denton, Director.
Office of Nuclear Reactor Regulation E), v.s.'*4*22 *E M
US Nuclear Regulatory Commission Q
s Washington, DC 20555 9/
/7' MIDLAND PROJECT MIDLAND DOCKET NOS 50-329, 50-330 RESPONSE TO OPEN ITEMS OF DRAFT SER SECTION 5.2.2 FILE: 0505.805 SERIAL:
13364 ENCLOSURE: RESPONSE TO OPEN ITEMS OF DRAFT SER SECTION 5.2.2 We have reviewed the preliminary d_ aft section of the NRC Staff's Safety Evaluation Report 5.2.2, " Overpressure Protection." Enclosed are our responses / comments to the open items contained within this draft section.
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JWC/ PEP /cr CC RJCook, Midland Resident Insper'_o.-
DSHood, NRC TPSpeis, NRC DBMiller, (3) Midland l
RWHuston, P-24-517
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PDR ADOCK 05000329 VI E
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1 OVERPRESSURE PROTECTION - DRAFT SER SECTION 5.2.2, RESPONSE TO OPEN ITEh3 The Draft SER on Overpressure Protection (5.2.2) received by Consumers Power Company contains the following NRC Reactor Systems Branch open items:
1.
Secord Safety Grade Reactor Trip Open Item Show that the overpressure calcul.aticas are conservative for anticipated transients assuming failure of the first reactor trip but with full credit for both spring actuated safety valves.
Response
Our position remains that total failure of the fir;t reactor trip is overly conservative for an abnormal operational transient. The above notwithstanding, we will perform overpressure calculations for the most severe abnormal operational transient rasuming failure of the first reactor trip and neglecting ARTS. Full credit will be taken for both spring actuated safety valves and normal anticipated performance of the Midland Plant. The results of this analysis are scheduled for submittal to the Staff by October 15, 1981.
For all other overpressure transients, the FSAR Chapter 15 analyses show
'cceptable results.
In addition, Midland has installed an ARTS which includes a high pressure trip utilizing sensors and hardware totally separate from the RPS thus providing an extra margin of safety against overpressure events.
2.
Analytical Models Open Item (a) Provide a complete description of the DYSID code used tu analyze inadvertent HPI operation.
Include all equations, assumptions and experimental verification. Provide comparisons between the DYSID code and the CADD code which has been approved by the NRC Staff.
Discuss the conservatism of the input assumptions used in the Midland DYSID analysis, in particular those for pressurizer level.
Response
DYSID is a pressurizer model subroutine which is incorporated into the CADDS code.
CADDS is documented in Topical Report BAW 10098.
The input assumptions to DYSID and analytical conservatisms are scheduled for submittal to the Staff by September 10, 1981.
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Open Item (b) The ?ower Train code utilized for overpressure protection analyses han not been approved by the NRC Staff. An additional information request was sent to B&W April 4, 1979, letter to J Taylor, B&W from S Varga, NRC, Review of Topical Report BAW-10070. Provide this requested information with a discussion of applicability to Midland.
Response
The B&W responses to the April 4,1979 request for inforr.ation for the Power Train code and benchmark comparison data are scheduled for submittal to the Staff by December 15, 1981.
Open Item (c) Provide the details of the CADDS verification program using plant startup data discussed on Page XIV-39 of NUREG-0460.
Response
The verification of the CADDS cade
. ing operating plant data was presented to the Staff in a meeting on June 25, 1981. The details of the CADDS verification will be documented and are scheduled for formal submittal to the Staf f b, September 10, 1981.
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oc0781-0133b131