ML19221A483
| ML19221A483 | |
| Person / Time | |
|---|---|
| Site: | Crane  |
| Issue date: | 04/08/1979 |
| From: | Mattson R Office of Nuclear Reactor Regulation |
| To: | Stern F GENERAL PUBLIC UTILITIES CORP. |
| References | |
| NUDOCS 7905230070 | |
| Download: ML19221A483 (3) | |
Text
-. -
April 8, 1979 Fred Stern, Manager Task Management / Scheduling TMI Recovery Organization The NRR Technical Review Team was briefed by Westinghouse (Clem Eicheidinger, et al.) on 4/7/79 on the preliminary conceptual design of modifications of the TMI-2 decay heat removal system.
The modifications are intended to increase the long term reliability of the DHR and to reduce its radiological impact on the auxiliary building and the environment in the event it is eventually needed to cool the TMI-2 core.
We understand that the DHR system is intended for use only in the event other preferred modes of long term cooling are not accomplished.
The existing DHR system is a redundant, two train system with a pump and heat exchanger in each train capable of delivering requi red flow and heat removal under normal core coolability conditions.
The conceptual design being developed by Westinghouse for GPU has three principal features, as follows:
1)
Provide piping andlsolation valves from existing DHR inlet piping to e location outside the auxiliary building where a permanent structure could be erected over the next six months to house a new, leaktight, DHR capable of running and cooling the core for several years with the present state of TMI-2 as the system design basis.
- 2) Add a third train to the present DHR system to increase its overall reliability for the short term (6 months) until the long term modification in item I is completed.
3)
Improve the leak tightness and the high radiation arecu p reliability of tne equipment in the existing two train DHR system.
The NRC staff fully endorses items 1) and 3) and urges that they be accomplished as soon as possible, in addition,with certain revisions that we believe can reasonably be accomplished in the relatively short time available (two to three weeks is assumed at this juncture), the staf f also endorses the second item.
Our suggestions for item 2, the third DHR train, a re as foll ows :
163 i33 7 9 0 5 2 3 0ao 7c) 2 l
Fred Stern April 8, 1979 a)
Find and use better (more leaktight) pumps than those currently being offerred by B&W (we are aiding in a nation-wide search for better pumps at this wri ting).
b)
Collect pump and valve leakage for confinement in a volume separate from the auxiliary building waste gas and liquid systems, but with remote control relief capability to those systems.
c)
Use welded connections.
d) Augment the normal DHR instrumentation to provide long term reactor coo! ant monitoring, sampling, un# chemistry control,cfc, e) Shield or obtain radiation hardened instrumentation.
f)
Build in preoperational leak detection capability.
g) Provide boron measurement and control for the reactor coolant system.
h) Use ASME code requirements where practical.
i)
Fredp9ree all equipment to extent practical.
j) Characterize piping and equipment seismic capability and provide OBE seismic capability to extent practical.
k) Provide administrative or design features to prevert DHR isolation by spurious high pressure or containment istlation signals.
1)
Provide for remo.te._ mon [toring_of pump sea _is.
Our suggestio_ns for item j, Improvement of the two existing DHR trains, a re a s fo l l mis -
a)
Collect pump and valve leakage for confinement in a volume separate f rom the auxiliary building waste gas and liquid systems, but with remote control relief capability to these systems.
b) Weld existing bolt i connections, where possible.
163 134 T
L Fred Stern April 8, 1979 c)
Shield or replace existing instrumentation with known radiation e -?d _: qual % b{ll d)
Leak test and weld leaks.
e) Augment instrumentation if not done for the third train, f)
Same as item k) for third train.
I believe it is imperative that GPU, Westinghouse and the NRC staff meet early tomorrow af ternoon to consider these suggestions and to mutually agree upon and freeze the conceptual design of the improved DHR system so that fabrication and installation can proceed as rapidly as possible.
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Roger on cc:
B. Arnold, GPU TR Review Team (8)
H. Denton V. Stello E. Case File 163 135
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.i Fred Stern,
'.a n a ge r Ta s k Managem:nt/Schedul ing TMI Recc.ery Crga..ization The f.'RR Techni ca l 2.2v ic.v Tean we.s b r i e f e d by
'r'e s t i r.ghous e (Clem Eicheldirgar, et al.) an 4/7/79 on the prclininary conccotuci de s i gn of mod i f ies t i c.is of t he T.".!-2 d.aca y hos t rc Sval s. s t. m.
The.edifications are intended to increcse the long tern reliability of the 3M3 and to reduce its radiological i r,, a c t on the 2 xilic ry buil ding cnd the cnvi ro.,~2nt in t'c e.+nt it is itu:lly
.. ceded to cool the 7d1-2 core.
Ue unders tcnd t: st tS.e CH3 :ysten is intend:d 'or use only in the event other preferred
.73 s of long t.r.u cooling are r.ot accc.)lis!ed.
The exis t i <g DHR sysic.a is a redundant, t.- a t r a i n s -s t a. t i t h a p m.: and %:et e,vc'a: ; r in -sch train ca.ctle,f
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g 63 136 W
Fred Stern Acril 8, 1979 a)
Find and use better (more leaktight) pumps than those currently being offerred by BSW (se are aiding in a nation-wide search for better cumps at this writing).
b)
Collect pump and valve leakage for confinement in a volume separate from the auxiliary building waste gas and liquid systemr, but with remote control relief capability to those systems.
c)
Use welded connections.
d) Augment the normal DHR instrumentation to provide long term reactor coolant nanitoring, sampling, c.1.1 chemistry control,cft,
e)
Shiel_ or obtain radiation hardened instrumentation.
f)
Build in preoperational leak detection capability.
g)
Provide boron measurement and control for the reactor coolant system.
h) Use A5ME code require.ents where practical.
e i)
Fredjgree all ecuipm2nt to extent practical, j)
Cheracterize piping and equip. ment seismic capability and provide 03E seismic capability to extent practical.
k)
Provide administrative or design features to prevent DhR isolation by spurious high pressure or containment isolation signals.
1)
Provide for r e..,o t e r.snitoring of pump seals.
Car suggastions for item 3, imprc c unt of the tso evistic; 3:.R t r s i ns,
are as f o l l o.:s :
a)
Collect pu p and salve leakage for <.onfine..ent in a.cl;r.e separate from the auxiliary building wes te gas ind licuid s y s t e.ms, but with rema*.e control relief capability to these s y s t a.m s.
b)
el d ex i s t ing bol t ed conc.ect ions, whe re pas s i b l e.
163 137
Fred Stern April 8, 1979 c)
Shield or replace existing instru,entation with known radiation u u al d W h i % d (l/
d)
Leak test and weld leaks'.
e) Augment instrumentation if not done for the third train.
f) Same as item k) for third train.
I believe it is imperative that GPU, tiestinghouse and the NRC staff uet ea rl y t onor ros af te rnoon to consider these suggestions and to c.utually agree upon and freeze the conceptual design of the inprosed DHR system so that fabrication and installation can proceed as rapidly as possible.
i (t h %
o Roger M ttson
(
cc:
- 8. Arncld, GPU TR Review Team (3)
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Stello E. Case Fila [
163 138 e