ML19322C474
| ML19322C474 | |
| Person / Time | |
|---|---|
| Site: | Davis Besse, Rancho Seco, Crane |
| Issue date: | 07/10/1979 |
| From: | Hebdon F Office of Nuclear Reactor Regulation |
| To: | |
| References | |
| TASK-TF, TASK-TMR NUDOCS 8001170801 | |
| Download: ML19322C474 (4) | |
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21 June 1979 Called lkGreen]at B&W.
He was the Site Operations Manager at Davis Besse..0n. August 9,1978 he wrote,_a letter to Davis-Besse concerning theiMa'rch 20 --1978: transient at(RanchoSeco)
- He wrote the memo because "someone" at B&W Lynchburg sent it to him to pass on to Toledo Edison.
- The site records at Lynchburg for Davis-Besse should say who sent it to him.
He doesn't remember.
- Jim Taylor at Lynchburg would be the person to contact.
l l
l 800117030/
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-26 June 1979
'k k fd h j$ (B&W)
-- returned my call to Jim Taylo
(.B_&W).concerningthe,leter to Davis Besse concerning._the.
h:2071978*RanchoiSecos incident, and the[,0(sij}8es,seL dent 7"~~~"
The Rancho Seco transient occurred March 20, 1978 and TMI had a similar transient on April 23, 1978.
There was considerable correspondence with each utility on each transietn.
(He'll send copies to me.)
Sent letterss to all utilities, except Met Ed concerning the Rancho Seco transient.
Decided not to send it to Met Ed because the material had already been discussed with them as a result of the analysis of the April 23, 1978 transient.
It was a conscious decision not to send it.
-- The specific fault (i.e., the dropped light bulb) at Rancho Seco was not applicable to TMI because TMI had a different " generation" of non-nuclear instrumentation
-- A similar letter was not sent out as a result of the Davis Besse Sept. 24, 1977 incident.
-- The incident was considered to be plant unique because:
1.
The Secondary Feed Rupture Control System (SFRCS) which started the transient was unique to Davis Besse.
2.
The PORV cycling was due to a missing relay.
3.
The PORV at Davis Besse was made by a different manufacturer than at any other plant.
They didn't analyze the scenario to see if a similar scenario could have occurred at other B&W plants.
9 July 1979 I
04ti 4 d Q } Q (NRR)
He prepared a meno on July 31, 1978 that noted PORV failure as a rpossible_cause of a rapid cooldown transient.
Related to the s
(March!20 [197811ncident at(Ri._sWSss.~o!
The comment was made by "someone" from NRC as an example of an additional cause of a rapid cooldown transient. This problem is assessed in some FSAR's as a cooldown transient but it's always bounded by the steam li:- break.
(Referred to Lanning 7/9.)
-- As far as Lobel knows the only action taken by the Task Group set up to investigate the incident was this meeting at SMUD.
B&W was supposed to run a small break LOCA analysis.
Lobel never saw it.
It would have been sent to SMUD and they may have decided not to forward it.
-- Zwetzig was in charge of the task force.
Lobel only wrote his summary for the information of his branch. He doesn't know if anyone else wrote a summary.
-- He'll send a copy of his file on the incident to me.
l
?
I 10 July 1979 Ca.
JA}$$1(NRR)aboutthe5EkIh10ElTdtransient
-- He headed the task group'that investigated the incident. He wrote the Stello memo assigning the tasks to Eisenhut and Grimes and the Reid memo setting up the tasks. The division between Grimes and Eisenhut was for the assignment of people (Lobel and Chiraman were in Eisenhut's AD).
-- His group did very little work other than the meeting at Rancho Seco because of the press of higher priority work.
They did:
1.
Determine it wasn't generic because Rancho Seco is the only B&W plant where an SFAS starts the auxiliary feed pumps.
2.
Started a change in the STS to require notifying NRC and getting NRC permission to start up following a rapid cooldown transient. Ray Klecker (in STS Branch) and Mort Fairtile (ORB) were working on the revised STS.
-- He recalls the brainstorming session on possible other causes, but he doesn't recall the PORV sticking being raised as a possible cause of a sudden cooldown. The p0RVcr n feticp would not cause much of a cooldown. Maybe the PORV sticks, pressure decreases, SFAS actuates, aux. feed initiates, and cooldown is the transient of j
concern. No one thought of any possible scenarios.
1