ML16340A634
| ML16340A634 | |
| Person / Time | |
|---|---|
| Site: | Diablo Canyon  |
| Issue date: | 10/12/1979 |
| From: | Major R, Savio R Advisory Committee on Reactor Safeguards |
| To: | Vassallo D Office of Nuclear Reactor Regulation |
| Shared Package | |
| ML16340A627 | List: |
| References | |
| NUDOCS 7911080203 | |
| Download: ML16340A634 (8) | |
Text
> ~ >> ~
~ i '
qadi 4~oui
+
~r' lip 0
r rr wP 0
UNITEDSTATES.
NUCLEAR REGULATORY.COMMISSION ADYISORY'COMINITTEEON REACTOR SAFEGUARDS WASHINGTON; D. C.20555 October, 12; 1979
'WP Q frI ~ <</<<P !
~
~
lw<<errr +>>
q D.. B. Vassallo, Acting Director, Division of Project Management
SUBJECT:
ACRS QUESTICNS REEATING TO CERTAIN NEAR-TERN OL PLANTS {DIABLO CANYONJ ZINGERt SEQUOYAH~ AND MCGUIRE)
Attached for your use are the questions. which have been prepared for con--
sideration during the anticipated ACRS Subcommittee meetings for, near-t rm operating
= licenses. on the>> Diablo Canyon, Zimmer, NcGuire, and Sequoyah nuclear. plants.
Please; let me knaw. when your staff can be.- prepared to discuss these issues so that= we can proceed with ACRS consideration of, these. projec~.,
A writteIT response.- is: preferred but the Subcoamittee would be prepared to.
(
discuss; these.matters;orally to facilitate-progress on thes matters.
Richard Savio-Staff Engineer.
ACRS Staff Richard K.
jor Reactor Engineer mRS Staff
Attachment:
As-stated Vclv 089
0
ACRS'UESTIONS REEATING TO CERTAIN NEAR-TERM OL PIANTS (DIABLO CANYONp Z2 PER'~
SEQUOYAH~ AND NCQUIRE)
I.
DIABLO CANYON AND SIHIEAR PLANTS:-
2'hat if'nything does-the NRC Staff think may warrant special consideration because of seismic considerations?
Has the Staff'considered-whether-special considerations are, re.-
quired with regard to operator response for a severe earthquake?
3.
4.
+at anomalies in system behavior during an earthquake should operators be trained to handle?
Is anything special required because of the, failure of non-seismically qualified equipment?
What, are the assumptions concerning, the failure of non-seismic, Class I piping?
To what extent can, the failuze of such piping be tolerated?
5.
Is-anything special. required with regard to reliability of con-nections to the-Refueling Water Storage Tank for the. earthquake situation'2 What criteria do the connections meet'?
6.
7.
8'.
What. significance is attached (if any) to recent cases of pipe cracking in. stagnant, borated water lines as it applies to earthquakes?:
What consideration, does-the. Staff believe appropriate for system degradation, such as the recent feedwater nozzle cracking. ex-
- pezience, as: it applies to inservice inspection programs for plants in areas: of high. seismic.
activity?'hat are-the seismic. classes-of:"
a PORV b.
Block Valve c..
Equipment related" to the operability of these devices d.
Pressurizer heaters and related equipment 9.
What are the specific. recommendations for the Auxiliary Peedwater System at Diablo Canyon?
What, is the dependence on AC power?
Are. there seismic effects in the control, zoom which require attention?
Has.. special consideration been given to structuzes, equipnent, and instrumentation in the contro1 room for an-earthquake situation?
Foe example.
Has the ceiling, been. analyzed?
Will lighting be: ade-quate?
Will,lighting fixtures and lights. remain in place?
What is. the status of control room instrumentation displays, how.= rapid is the. plant process computer.
(delay between-printing..
and, real, time), and what. effect, would, an earthquake have'?
12'.
How comprehensive are tests for electrical transients during an earthquake and what is the effect, on equipnent?
What is the reliability of both off-site-and on-site power?.
13-.
What are the Staff conclusions regarding technical support capa-bilities for Diablo Canyon.
ZI HER AND SIMILAR PLANTS:
What are the Staff's specific recommendations on BWRs as they related to 241 Implications Lessons-Learned'?
How. will.,they be implemented?
2.
What has been the review-for the reliability of decay heat removal systems for anomalous transients?
~
3 Has; the Staff.reviewed procedures: for transients; and accidents?.
What" has; been. the conclusion?
What. has. been the NRC'taff's consideration of. the advantages-and disadvantages of a-filtered and'. vented containment (see attached,.
"Additional Comments" from Interim Report No.
3 on 'three-Mile Island Nuclear; Unit 2, May 16, 1979)'?
Are there procedures. for cases where-one. train of a: system is down for maintenance and the other train fails?
6..
During transients; what, actions could an. operator take-to fur-ther aggrevate a situation?,
Are there procedures noting actions operators should not take?
7.
What. in the way of a systems interactions study has been performed at Zimmer?
How is the. potential for adverse systems. interactions expl'o red?'.
What is the type of display and. use of instrumentation describing the status of. the core?
9..
10..
How fast.'can the plant process computer respond'o severe transients?'ow close! to~ real time-is: the printed. output in the: control. room?
To. what extent has the Staff considered. anomalous feedwater transients, such. as overfill,. in BWRs?'
E
- III, SEQUOYAH AND MCGUIRE PM3'IMILAR ICE CONDENSER/UHI. PLANTS 1..
Discussion as-to special features of the ice condenser/UHI plants which would require considerations in the light of'he TMI-2' accident.
The discussion should include hydrogen control.
and, inert. gas blockages in the primary system.
2 D's ssion as to, the information which would be available. to the.
lscusslo operator, in the control room in the event of a severe trans'ent.
3..
Discussion of the NRC Staff's review of the emergency control room procedures for Sequoyah and McGuire.
4.
Status of the NRC Staff's review of possible plant transients, including a discussion as to what extent the Staff has 1'ooked at ways in which operator action may increase. the consequences of the transients.
5.
Discussion as, to the reliability of the decay heat, removal, systems following anomalous. transients..
6..
What has. been the. NRC Staff s consideration of the advantages and.
disadvantages= of a filtered and vented containment?'
Wh t
~" specific. recommendations for. the-auxiliary feedwater a
are.
- AC.
.systems-for.. Sequoyah; and. McGuire?;
What is, the dependence on; gower?
I