ML20062B538

Advises That Util Will Not Propose Any Mods to Current Program at Facility Since Plant Operation Through Dec 1978 Has Not Provided Basis for Determining Mods.Asserts That Use of ASME Section XI Draft 2 Rules Would Not Be Practical

ML20062B538
Person / Time
Site:	Fort Saint Vrain
Issue date:	10/19/1978
From:	Justin Fuller PUBLIC SERVICE CO. OF COLORADO
To:	Speis T Office of Nuclear Reactor Regulation
References
P-78169, NUDOCS 7810310094
Download: ML20062B538 (3)

Text

'

47 p

g

,\ public Service Company *2 CoDomdle P.O. BOX 840 DENVER, COLORADO 8o201 e fm October 19, 1978 Fort St. Vrain Unit No. 1 P-78169 Mr. Themis P. Speis. Chief Advanced Reactors Branch

[ j,~

4 Division of Project Managemerit by ^}[;.

' / ~-

U.S. Nuclear Regulatory Commission Washington, DC 20555 "'e ,

Subject:

In-Service Inspection--Fort St. Vrain

Dear Mr. Speis:

This is in reply to your letter of August 28, 1978 on the above subject which refers to paragraph 3.3.3 of the USAEC Safety Evaluation Report of Jan-uary 20,1972 (SER). This paragraph provides that the applicant (Public Service Company of Coloyado, PSC) will review the Fort St. Vrain (FSV) in-service inspection program after five years of operation and, at that time, propose any necessary moditications. In your letter of August 28, 1978 you note that five years of reactor operation will have elapsed in January 1979 and you anticipate _that the results of our review would be submitted shortly after that date.'

PS has been rcviewing, as a continuing effort, the inspection program define in the Technical Specifications and currently in force at FSV. Plant opera on through 1978 does not offer sufficient basis for modifying the cur-ren rogram. PSC does not intend to forward proposed modifications to its cyrent program shortly after January 1979.

The reasons why plant operation through December 1978 has not provided a basis for making any proposed modifications are:

During the 26 month period between initial reactor criticality in Jan- -

uary 1974 and March 1976 when 30 percent power was first achieved, the reactor was at or below the two percent power level. Furthermore, for 21 months of the 26 month period, the reactor was shut down. As a result there has been insufficient operating time at significant tem-perature and power level to accumulate meaningful findings.

Significant di ficiency or weakness in the presently defined program has not been revealed by its implementation.

~

7 9

9 781031 oo W P \

. i - ._ - -. .- - ..-

l.s%

, y,. ,.yr 2 Pusuc S cRvicc COMPANY OF COLOR ADO DATE 10/19/78

. P-78169 In-hervice Inspection--Fort St. Vrain With regard to our verbal commitment to NRC to review the applicability of current nuclear power plant in-service inspection rules to FSV, PSC has twice reviewed the FSV design, using the requirements delineated in the Code of Federal Regulations. Title 10, Part 50.55a, paragraph (g), and the ASME Code,Section XI, Division 1 and Division 2.(in draft) for guidance, as sug-gested in your letter of August 28, 1978. The first review, which was performed in the spring of 1976, resulted in a decision to await clarification of the applicability of 10CFR50.55a(g) to gas reactors and for further progress by the ASME on Section XI, Division 2. The second review, conducted during the summer of 1978, was based on the current draft of Division 2 of Section XI of the ASME Code, " issued for revi'.w and comment until September 15, 1978". PSC forwarded some comments on this draf t t'o the ASME on September 1,1978 (copy enclosed).

The above reviews have encompassed both evaluation of the applicability i of the ASME,Section XI, Division 2 (draft) rules to the FSV plant and a detailed comparison of these rules with the Technical Specification Surveillance Requirements. From this work we have concluded that application of Division 2, as it is presently constituted, would not provide earlier or better information concerning the level of plant safety being maintained or deterioration of safety related factors than the surveillance program already defined and in force.

But its application could entail considerably increased costs, both direct and those associated with reduced plant availability.

Two of the more important reasons for this are:

Division 2 does not adequately consider the generic differences between LWR plants and HTGRs, particularly those associated with the inherent safety superiority of HTGRs.

Division 2 does not adequately consider the significant differences between Fort St. Vrain and proposed large HTGRs, nor can it be expected to.

A philosophy shift from Division l's pressure boundary concern,to concern based on safety function as determined by operational role, is stated in the forward of Division 2. However, the Division 2 organization and format essen-tially parallels that of Division 1. Assignment of classifications which deter-mine nature and extent of inspection is required like Division 1. But how cognizance is to be taken of operational role, designed in redundancy, or safety systems always in operation is not made clear. Following the organizational format could result in assignment of classifications to hundreds of items which would involve expensive and time consuming inspections of factors not necessary for maintenance of an adequate safety level. We presently believe the philos-ophy statement is more effectively implemented by the FSV surveillance program presently in force than by the inspection program that would result from adherence to the form and content of the present Division 2 draft.

Our review program is continuing. The program is presently focusing on developing safety categories and boundaries that are realistically related to

% k

s  : .

~

• ' ~

Pusuc S avice CCMPANYCF C5t CCADD Om 10/19/78

- [ *u.bi p,r

' In-Service Inspection--Fort St. Vrain the safety role of systems and components and fully consider the design philosophy and inherent safety superiority of Fort St. Vrain over LWR plants.

Our effort also encompasses inspection requirements and frequency, acceptance criteria, exemption criteria, and examination techniques.

There are uncertainties arising out of the continuing startup program of the plant which make it difficult to estimate completion of our program. For example, the final configuration of plant systems may be different than they are now and different surveillance measures may be needed. However, we believe there will have been sufficient progress by September 30, 1979 to enable a completion date estimate to be attempted. We will report our progress to you by September 30, 1979 and, if possible, estimate a completion date for our review program. We do not an'ticipate any change in the surveillance program presently in force for the Fort St. Vrain plant until we complete our review program. We will continue with its implementation during the first Fort St.

Vrain refueling outage.

Very truly yours,

.K. Fuller, Vice President Engineering and Planning JKF/RS

( .

~

e D

i

_ _ _ - _ _..__m_._