ML19261F313

RO 77-22/1T:on 770825,B&W-required Operating Restrictions on Decay Heat Removal Pumps Found Contrary to Description of Pump Operating Capability Per Fsar.Caused by B&W Failure to Perform Safety Evaluation.Corrective Action by 770923.W/LER

ML19261F313
Person / Time
Site:	Three Mile Island
Issue date:	09/09/1977
From:	Herbein J METROPOLITAN EDISON CO.
To:
Shared Package
ML19261F314	List: ML19261F313 ML19261F315
References
GQL-1228, NUDOCS 7910250774
Download: ML19261F313 (4)

Text

.

/ N s u.s. NUCLEAR REcutATony issioN TN NRC Pomu 195 DOtC"o UMBER 2g9 c.r.,

l

. .NRC DISTRIBUTION PoR PART 50 DOCKET MATERIAL INCIDENT DEPORT oATE cr occuuENT iTO: B H Grier FROM: Metropolitan Edison Co 9 9-77 Reading, Pa #7'"'"

l J G Herbein ' 9-15 77 6

C NOTO RIZ E D PRCP INPUT FORM NUMBER OF CCPIES RECE.VED hETTER ORIGINAL y Nc LAgg g plE D

" c =" I siy ch i CEsCRIPTION EN CLCSU R E l- Licensne Event Recort (RC# 77 22/lT) on 8 25-7:

concerning operating restrictions en the decay heat removal pumps found contrary to pumps ep r-ating capacity as defined in tech soacs ......

3p 1p

? TANT NAME: Three Mile Island #1 l 9-15 77 ehf NOTE: IF PERSONNEL EXPOSURE IS INVOLVED SEND DIRECTLY TO KREGER/J. COLLINS

/ dY 6Nec R ec.9

• FOR ACTION /INFORMATION

! ooAncy enter. kf M I vt 7 cyq rno AcTTnn tTc AqqT_- 1AJA F Am t

INTERNAL DISTRIBUTION C. AT p vpr pnp i ,er (o) I .

I I vvpc I I ccunnenrR /IPPOLITO unriqTen i I yne w / curry I I c,vre I i

rvvnne i

nt-vro n An Attro nrsen c 'q rVMTTT QAFQ enin

'_'nt f Vr4 /9FNc4

'IQrNFQ / T_ cnTTTN9 nou EXTERNAL DISTRIBUTION CONTROL NUM BE R I e pnn # ARA.S buire PA. l .

m. v i i o 82 02Q /

I ACRS (16) SENT AS dAT ,8 #7 S803 SC 'l 2

7 y; oa 3o77p p

s 7

L &.Le t17av a

. Poet

• POM PMQ0A133 METROPOLITAN EDISON COMPANY _ _ -

. _- 1.

POST OFFICE BOX $42 READING, PENNSYLV ANI A 19603 TELEPHONE 215 - 9290001 September 9, 1977 GQL 1228 Mr. Boyce H. Grier, Director -

Office of Inspection and Enforcement, Regicn I ddII ,' -

U.S. Nuclear Regulatory Cct=ission -3; -

631 Park Avenue . ~"

King of P*ur sia, PA 19hC6 s

Dear 35.r /

Decket No. 50-289 Operating License No. DPR-50 In accordance vith the Technical Specifications of our Three Mile Island Nuclear Station, Unit I (TMI-1), we are reporting the following reportable occurrence:

1) Report Ncnber: 77-22/lT 2a) Required Report Date: 9/8/77*

2b) Date of Cccurrence: 8/25/77

3) Facility: fhree Mile Island Nuclear Station, Unit 1 h) Identification of Occurrence:

Title:

Restrictions were Placed on the Decay Heat Receval Pumps Type: A reportable occurrence as defined by 6.9 2. A.9 'n that required operating restrictions on tne Decay Heat Re= oval Pumps were found centrary to the description of the pumps operating capability in the FSAR.

5) Conditions Prior to Occurrence: ,

Power: Core 1005 Elec. 811 MWe Gross RC Flow:

RC Pressure:

lh5x106 lb/hr 2163 psig }k02 {

RC Temp: 579CF PRZR Level 227 inches PR' 'S Te- - 652c

' ~ ^

gQ{jgO3hO

• A detailed report regarding Met-Ed's additional September 3/h vibraticn test, UT tests, and stress analysis to confirm the continued reliability of TMI-l Decay Heat ?u=ps was presented to R. W. Reid at the NRR 3ethesda offices on 9-8-77.

Mr. Boyce H. Grier, Director September 9, 1977 GQL 1228

6) Descriptien of Occurrence:

During the preparatien of a procedural change to incorporate recent recc==endations by the Nuclear Steam Supply Systems (NSSS) vender restricting the operations of Decay Heat Removal Pumps at mini =u= recirculatien flow rates, it was recognized that these restrictions were contrary to the FSAR statement that the Decay Heat Removal Pu=ps could operate " indefinitely" in the minimum recirculation mode (FSAR Secticn 6.1.2.1.2). These restrictions were developed to minimize the potential for an occurrence similar to a Eecay Heat Removal Pu=p shaft failure which had been reported at ancther utility's site.

7) Apparent Cause of Cecurrence:

The Decay Heat Remova.1 Pu=p shaft at another utility's site failed during preoperational testing. Therefore, operating restricticns were prc=ulgated by the NSSS vendor without a full investigation into the cause for failure and without a formal safety analysis by the NSSS vender.

3) Analysis of Occurrence:

The analysis of the reliability of the Decay Heat Removal Pu=ps has been detailed to the US:TEC Director of Nuclear Reactor Begulation by a separate letter dated 9/6/77. The conclusien of that analysis was that although lov flow rates can lead to relatively higher leads on the pu=p, vendor experience with similar pumps indicates that intermittent operaticn at recirculation flow rates, totalling many hours over the life of the pu=ps, vill not damage the pumps; furthermore, the requirements of the safety analysis (FSAR Section ik) for operaticn of the Decay Heat Removal Pu=ps in the recirculation mode can be met by the presently designed syste= and equipment.

9) Corrective Action:

(To be submitted on September 23, 1977, per telecen with Mr. Struter en September 9, 1977.)

e

Mr. foyce H. Grier, Director September 9, 1977

, GQL 1223

10) Failure Data:

Decay Heat Removal Pump Manufacturer: Worthingten Model "o.: 3 Wn ISL Part No. 2 (shaft)

Material: SA-56h Type 630 ET 1150 Similar Occurrence:

Ncne c'ncerely,

'/ ,

, J. G. Herbein Vice President JGH:DGM:ies

Attachment:

LER 1482 032

.