ML20211D330

Comments on Program Plan for Utilizing Facility Experiences & Technical Support Activities to Best Advantage in Advanced HTGR Safety Studies.Focus of Program Plan Should Be Limited to Few Critical Areas

ML20211D330
Person / Time
Site:	Fort Saint Vrain
Issue date:	10/16/1986
From:	Miraglia F Office of Nuclear Reactor Regulation
To:	Speis T Office of Nuclear Reactor Regulation
References
TAC-60400, NUDOCS 8610220170
Download: ML20211D330 (5)

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UNITED STATES i

f NUCLEAR REGULATORY COMMISSION o

I WASHWGTON, D. C. 20886

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Otober 16, 1986 4.4

• Docket No. 50-267 MEMORANDUM FOR: Themis P. Speis, Director Division of Safety Review and i

Oversight FRON:

Frank J. Miraglia, Director 3

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Division of PWR Licensing-B

SUBJECT:

COMMENTS ON PROGRAM PLAN FOR UTILIZING TO BEST ADVANTAGE FORT ST. VRAIN IXPERIENCES AND TECHNICAL SUPPORT ACTIVITIES IN ADVANCED HTGR SAFETY STUDIES s

Reference:

Memorandum from T. Speis dated October 6, 1986 on same i

subject.

l My staff has reviewed your proposed program plan. Our general comments fo? low, along with specific comments in the enclosure.

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Our first concern is that we may not need to undertake a program of this scope and magnitude to support licensing of an advanced HTGR application. Also, i

DPWRL-B's resources to support this program and its licensing responsibilities are limited. This is especially true for FY-87, during which time we will have to reduce the project management staff for Fort St. Vrain. Thus, we have tried to focus your proposal on specific areas that we believe are most relevant to HTGR safety, based on the Fort St. Vrain experience.

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Second, Fort St. Vrain's future operation is likely to be subject to much greater scrutiny concerning costs and benefits than its past operation.

It may be increasingly difficult to identify tasks that are beneficial to both Public Service Company of Colorado and to the future HTGRs. However, this could be potentially offset if funding came from either RES, DOE, or GA Technologies.

For the above reasons we recomend that the focus of the program plan be limited to a few critical areas. Our recommendations for specific areas are given in the enclosure, i

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'i 8610220170 861016 PDR ADOCK 05000267 p

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, l Ongoing Fort St. Vrain operational data collection and studies submitted on the docket would, of course, be available to your proposed program. We will cooperate with you in assuring that this information is properly utilized by other offices and agencies.

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Frank J.

ragl'ia, Director Division of PWR Licensing-B

Enclosure:

1 As stated cc w/ enclosure:

R. Williams, DSR0 T. King, DSRO

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G. L. Plumlee, FOB R. D. Martin, Regional Administrator, RIV E. S. Beckjord, Director,

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Enclosure Comments on Safety Issues Comon to Advanced HTGRs and Fort St. Vrain (FSV)

Issue 1 -

For FSV, only limited capabilities in this area are needed.

SEVERE ACCIDENTS This may include a capability to analyze severe accidents.

AND PROBABILISTIC This would basically serve as a check on the licensee's RISK ASSESSMENT capabilities in this area. A limited capability to do (High Priority)

PRAs for one or two accident types may be useful to support the Technical Specification Upgrade Program.

We have begun one task in this-area on FSV's DBA-2.

Issue 2 -

We find that graphite material performance is satisfactory GRAPHITE STRUCTURAL and do not have a need for further work at this time (also MATERIALS seeIssue14).

(Low Priority)

Issue 3 -

We support further work on this to the extent that it

. FLUID MECHANICS supports Issue 1 and our general capabilities to deal with ANALYSIS AND FSV issues (i.e., verify cooldown analyses).

BENCHMARKING (High Priority)

Issue 4 -

We consider this issue closed until further data indicate FLOW INDUCED otherwise.

EFFECTS ON CORE STRUCTURE (LowPriority)

Issue 5 -

Combustion of graphite does not seem to havs major significance COMBUSTIBLE GAS for gas cooled reactors.

GENERATION (Low Priority)

Issues 6 & 7 -

Good fuel performance seems to reduce the significance of FISSION PROD' JCT these issues.

RELEASE-FUEL PARTICLE INTEGRITY (MediumPriority)

Issue 8 -

We are not sure of the gene"ic significance of FSV experience.

HUMAN FACTORS This should be discussed with DHFT.

FSV has many complex (Lew Priority) subsystems because it is a prototype. Hopefully, future plants will reflect mature and simpler designs.

Issues 9 & 10 -

'We do not see the relevance to FSV.

HTGR SAFETY HAND-BOOK & CODE LIBRARY (Low Priority)

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t Issue 11 -

The focus here for FSV would be on reliable operation HELIUM CIRCULATORS with minimal water ingress. The key appears to be (Medium Priority) circulator auxiliaries, especially control and power systems. However, the. advanced HTGR may use other technologies and, therefore, not share the FSV problems.

Issues 12 & 13 -

FSV work can guide advanced reactors, but no radically ISI&T AND PCRV new work on FSV is needed. We are continuing with TENDON CORROSION licensing activities. Also, the advanced HTGR uses a (Low Priority) steel reactor vessel, with different problems.

Issue 14 -

The FSV fuel program has shown good performance to date.

FUEL BLOCK However, no fuel has gone the full six cycles. Continued CRACKING operation of FSV is important to fuel technology for the (HighPriority) advanced HTGR.

Issue 15 -

The design features of any advanced HTGR would have to be RECENT FSV

. reviewe,d carefully against all applicable rules and LICENSING ISSUES significant guidance. FSV experience is relevant, and (Medium Priority) should be highlighted in this process.

October-16, 1986

. Ongoing Fort St. Vrain operational data collection and studies submitted on the docket would, of course, be available to your proposed program. We will cooperate with.you in assuring that this information is properly utilized by other offices and agencies.

Origirm1 signed by Frank J. Miraglia Frank J. Miraglia, Director Division of PWR Licensing-B

Enclosure:

As stated cc w/ enclosure:

R. Williams, DSR0 T. King, DSR0 G. L. Plumlee, F0B R. D. Martin, Regional Administrator, RIV E. S.'Beckjord,-Director,

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