ML12130A318

Email from Barry Quigley to Bill Borchardt 2.206 Petition for Braidwood-Byron Turbine High Energy Line Break

ML12130A318
Person / Time
Site:	Byron, Braidwood
Issue date:	04/20/2012
From:	Quigley B Members of the Human Race
To:	Borchardt R NRC/EDO
Joel Wiebe
References
2.206
Download: ML12130A318 (3)

Text

Cathy From: t3arry Quigley [quigley10cfr@gmail.com]

Sent: Friday, April 20. 2012 6:44 AM To: Borchardt, Bill Cc: Pederson.

Cynthia; Duncan. Eric; Bartlett.

Bruce; Robbins. John

Subject:

2.206 Petition for Turbine Building HELB Attachments:

3yron 2-206 Petition.

doc Mr. Borchardt, Please see attached petition regarding Byron and Braidwood HELB. Some aspects of the issue are complex, am available to provide additional explanation as needed. I believe that prompt action is Bar:y 815-406-2005 (daytime number)

CI Re: Byron & Braidwood High Energy Line Breaks Mr. Borchardt, This 2.206 petition requests NRC to require Exelon Nuclear's Byron and Braidwood Units 1 and 2 to be immediarely shutdown until all Turbine Building (TB) High Energy Line Break (HELB) concern::;

are idemified and those imponant to safety are corrected.

Background The physical layout of the Byron and Braidwood plants exposes both lrdins of emergency electric power generation.

emergency AC distribution, ESF batteries and DC distribution to the effects of non-safety related piping failures.

Although the areas of concern are in the safety-related auxiliary building, they directly connect to the turbine building via ventilation openings in the common wall between the auxiliary and TUrbine buildings.

The openings range in size from 5 ft2 to 40 n2. The design t1aw was missed by the licensee and NRC reviewers during initial licensing in the mid-to late-80s.

he poteltiat to disable multiple all trains of safety-related t:quipment was first identifIed in 1991 An analysis was done in response which credited closure of fire dam t ers to .wuiPment, however the analysis scope was limited due to the compressed schedule to respond to the NRC. In 1996, additional analysis was done to in response to single failure concerns of the fire dampers. Piping stresses analyses were done to eliminate some break locations, however the work stopped far short of a comprehensive review of the HELB regulato:-y requirements.

BUliisfor Rl;fqueli{

The major are: An adequate supnly or combustion air for the diesel generators is threatened because the combustion air can be diluted with steam. Although the combustion air is drav;11 from an air shaft (not the turbine building), it is also the same air shaft that supplies ventilation for the DO room. Under certain conditions, the ventilation damper alignment is such that steam that enters the DG room from the ventilation exhaust can back flo"'" into the inlet air shaft. From there it can be drawr. into the engine, potentia!):, starving the engine of air. The effects of high temperature in the ESP switchgear rooms on the protective relaying setpoints has not been evaluated.

The conccm is that high temperatures could alter the setpoints such that protective actions occur W1der normal loading condi':ions.

S:;O -G20120269 The current method of analysis for TB HELB uses a "lumped volume" approach wherei'1 the mass and energy of the ruptured line mixe$ instantly

"'lith the entire volume before flowing into the areas of concern. Since this substantially reduces the flow, it does not always give conservative results. For example, a preliminary assessment using the sub-divided volume feature in GOTE!C shows that structuraJ limits on the block wall between the ESF switchgear rooms would Je substantially exceeded. There l1as been no structured and detailed review of the licensing .requirements for E:::LB.

.,' Barry 3512 Louisiara Rockford, TL I: 11 -2 ...